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powerpc: Fix broken cpu_idle_wait() implementation
[linux/fpc-iii.git] / net / ipv4 / route.c
blob0197747961748aff73465a90bd689d70b3113880
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * ROUTE - implementation of the IP router.
7 *
8 * Authors: Ross Biro
9 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10 * Alan Cox, <gw4pts@gw4pts.ampr.org>
11 * Linus Torvalds, <Linus.Torvalds@helsinki.fi>
12 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
13 *
14 * Fixes:
15 * Alan Cox : Verify area fixes.
16 * Alan Cox : cli() protects routing changes
17 * Rui Oliveira : ICMP routing table updates
18 * (rco@di.uminho.pt) Routing table insertion and update
19 * Linus Torvalds : Rewrote bits to be sensible
20 * Alan Cox : Added BSD route gw semantics
21 * Alan Cox : Super /proc >4K
22 * Alan Cox : MTU in route table
23 * Alan Cox : MSS actually. Also added the window
24 * clamper.
25 * Sam Lantinga : Fixed route matching in rt_del()
26 * Alan Cox : Routing cache support.
27 * Alan Cox : Removed compatibility cruft.
28 * Alan Cox : RTF_REJECT support.
29 * Alan Cox : TCP irtt support.
30 * Jonathan Naylor : Added Metric support.
31 * Miquel van Smoorenburg : BSD API fixes.
32 * Miquel van Smoorenburg : Metrics.
33 * Alan Cox : Use __u32 properly
34 * Alan Cox : Aligned routing errors more closely with BSD
35 * our system is still very different.
36 * Alan Cox : Faster /proc handling
37 * Alexey Kuznetsov : Massive rework to support tree based routing,
38 * routing caches and better behaviour.
39 *
40 * Olaf Erb : irtt wasn't being copied right.
41 * Bjorn Ekwall : Kerneld route support.
42 * Alan Cox : Multicast fixed (I hope)
43 * Pavel Krauz : Limited broadcast fixed
44 * Mike McLagan : Routing by source
45 * Alexey Kuznetsov : End of old history. Split to fib.c and
46 * route.c and rewritten from scratch.
47 * Andi Kleen : Load-limit warning messages.
48 * Vitaly E. Lavrov : Transparent proxy revived after year coma.
49 * Vitaly E. Lavrov : Race condition in ip_route_input_slow.
50 * Tobias Ringstrom : Uninitialized res.type in ip_route_output_slow.
51 * Vladimir V. Ivanov : IP rule info (flowid) is really useful.
52 * Marc Boucher : routing by fwmark
53 * Robert Olsson : Added rt_cache statistics
54 * Arnaldo C. Melo : Convert proc stuff to seq_file
55 * Eric Dumazet : hashed spinlocks and rt_check_expire() fixes.
56 * Ilia Sotnikov : Ignore TOS on PMTUD and Redirect
57 * Ilia Sotnikov : Removed TOS from hash calculations
58 *
59 * This program is free software; you can redistribute it and/or
60 * modify it under the terms of the GNU General Public License
61 * as published by the Free Software Foundation; either version
62 * 2 of the License, or (at your option) any later version.
63 */
64
65 #include <linux/module.h>
66 #include <asm/uaccess.h>
67 #include <asm/system.h>
68 #include <linux/bitops.h>
69 #include <linux/types.h>
70 #include <linux/kernel.h>
71 #include <linux/mm.h>
72 #include <linux/bootmem.h>
73 #include <linux/string.h>
74 #include <linux/socket.h>
75 #include <linux/sockios.h>
76 #include <linux/errno.h>
77 #include <linux/in.h>
78 #include <linux/inet.h>
79 #include <linux/netdevice.h>
80 #include <linux/proc_fs.h>
81 #include <linux/init.h>
82 #include <linux/workqueue.h>
83 #include <linux/skbuff.h>
84 #include <linux/inetdevice.h>
85 #include <linux/igmp.h>
86 #include <linux/pkt_sched.h>
87 #include <linux/mroute.h>
88 #include <linux/netfilter_ipv4.h>
89 #include <linux/random.h>
90 #include <linux/jhash.h>
91 #include <linux/rcupdate.h>
92 #include <linux/times.h>
93 #include <linux/slab.h>
94 #include <linux/prefetch.h>
95 #include <net/dst.h>
96 #include <net/net_namespace.h>
97 #include <net/protocol.h>
98 #include <net/ip.h>
99 #include <net/route.h>
100 #include <net/inetpeer.h>
101 #include <net/sock.h>
102 #include <net/ip_fib.h>
103 #include <net/arp.h>
104 #include <net/tcp.h>
105 #include <net/icmp.h>
106 #include <net/xfrm.h>
107 #include <net/netevent.h>
108 #include <net/rtnetlink.h>
109 #ifdef CONFIG_SYSCTL
110 #include <linux/sysctl.h>
111 #endif
112 #include <net/secure_seq.h>
113
114 #define RT_FL_TOS(oldflp4) \
115 ((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
116
117 #define IP_MAX_MTU 0xFFF0
118
119 #define RT_GC_TIMEOUT (300*HZ)
120
121 static int ip_rt_max_size;
122 static int ip_rt_gc_timeout __read_mostly = RT_GC_TIMEOUT;
123 static int ip_rt_gc_interval __read_mostly = 60 * HZ;
124 static int ip_rt_gc_min_interval __read_mostly = HZ / 2;
125 static int ip_rt_redirect_number __read_mostly = 9;
126 static int ip_rt_redirect_load __read_mostly = HZ / 50;
127 static int ip_rt_redirect_silence __read_mostly = ((HZ / 50) << (9 + 1));
128 static int ip_rt_error_cost __read_mostly = HZ;
129 static int ip_rt_error_burst __read_mostly = 5 * HZ;
130 static int ip_rt_gc_elasticity __read_mostly = 8;
131 static int ip_rt_mtu_expires __read_mostly = 10 * 60 * HZ;
132 static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
133 static int ip_rt_min_advmss __read_mostly = 256;
134 static int rt_chain_length_max __read_mostly = 20;
135
136 static struct delayed_work expires_work;
137 static unsigned long expires_ljiffies;
138
139 /*
140 * Interface to generic destination cache.
141 */
142
143 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie);
144 static unsigned int ipv4_default_advmss(const struct dst_entry *dst);
145 static unsigned int ipv4_mtu(const struct dst_entry *dst);
146 static void ipv4_dst_destroy(struct dst_entry *dst);
147 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst);
148 static void ipv4_link_failure(struct sk_buff *skb);
149 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
150 static int rt_garbage_collect(struct dst_ops *ops);
151
152 static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
153 int how)
154 {
155 }
156
157 static u32 *ipv4_cow_metrics(struct dst_entry *dst, unsigned long old)
158 {
159 struct rtable *rt = (struct rtable *) dst;
160 struct inet_peer *peer;
161 u32 *p = NULL;
162
163 if (!rt->peer)
164 rt_bind_peer(rt, rt->rt_dst, 1);
165
166 peer = rt->peer;
167 if (peer) {
168 u32 *old_p = __DST_METRICS_PTR(old);
169 unsigned long prev, new;
170
171 p = peer->metrics;
172 if (inet_metrics_new(peer))
173 memcpy(p, old_p, sizeof(u32) * RTAX_MAX);
174
175 new = (unsigned long) p;
176 prev = cmpxchg(&dst->_metrics, old, new);
177
178 if (prev != old) {
179 p = __DST_METRICS_PTR(prev);
180 if (prev & DST_METRICS_READ_ONLY)
181 p = NULL;
182 } else {
183 if (rt->fi) {
184 fib_info_put(rt->fi);
185 rt->fi = NULL;
186 }
187 }
188 }
189 return p;
190 }
191
192 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr);
193
194 static struct dst_ops ipv4_dst_ops = {
195 .family = AF_INET,
196 .protocol = cpu_to_be16(ETH_P_IP),
197 .gc = rt_garbage_collect,
198 .check = ipv4_dst_check,
199 .default_advmss = ipv4_default_advmss,
200 .mtu = ipv4_mtu,
201 .cow_metrics = ipv4_cow_metrics,
202 .destroy = ipv4_dst_destroy,
203 .ifdown = ipv4_dst_ifdown,
204 .negative_advice = ipv4_negative_advice,
205 .link_failure = ipv4_link_failure,
206 .update_pmtu = ip_rt_update_pmtu,
207 .local_out = __ip_local_out,
208 .neigh_lookup = ipv4_neigh_lookup,
209 };
210
211 #define ECN_OR_COST(class) TC_PRIO_##class
212
213 const __u8 ip_tos2prio[16] = {
214 TC_PRIO_BESTEFFORT,
215 ECN_OR_COST(BESTEFFORT),
216 TC_PRIO_BESTEFFORT,
217 ECN_OR_COST(BESTEFFORT),
218 TC_PRIO_BULK,
219 ECN_OR_COST(BULK),
220 TC_PRIO_BULK,
221 ECN_OR_COST(BULK),
222 TC_PRIO_INTERACTIVE,
223 ECN_OR_COST(INTERACTIVE),
224 TC_PRIO_INTERACTIVE,
225 ECN_OR_COST(INTERACTIVE),
226 TC_PRIO_INTERACTIVE_BULK,
227 ECN_OR_COST(INTERACTIVE_BULK),
228 TC_PRIO_INTERACTIVE_BULK,
229 ECN_OR_COST(INTERACTIVE_BULK)
230 };
231
232
233 /*
234 * Route cache.
235 */
236
237 /* The locking scheme is rather straight forward:
238 *
239 * 1) Read-Copy Update protects the buckets of the central route hash.
240 * 2) Only writers remove entries, and they hold the lock
241 * as they look at rtable reference counts.
242 * 3) Only readers acquire references to rtable entries,
243 * they do so with atomic increments and with the
244 * lock held.
245 */
246
247 struct rt_hash_bucket {
248 struct rtable __rcu *chain;
249 };
250
251 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
252 defined(CONFIG_PROVE_LOCKING)
253 /*
254 * Instead of using one spinlock for each rt_hash_bucket, we use a table of spinlocks
255 * The size of this table is a power of two and depends on the number of CPUS.
256 * (on lockdep we have a quite big spinlock_t, so keep the size down there)
257 */
258 #ifdef CONFIG_LOCKDEP
259 # define RT_HASH_LOCK_SZ 256
260 #else
261 # if NR_CPUS >= 32
262 # define RT_HASH_LOCK_SZ 4096
263 # elif NR_CPUS >= 16
264 # define RT_HASH_LOCK_SZ 2048
265 # elif NR_CPUS >= 8
266 # define RT_HASH_LOCK_SZ 1024
267 # elif NR_CPUS >= 4
268 # define RT_HASH_LOCK_SZ 512
269 # else
270 # define RT_HASH_LOCK_SZ 256
271 # endif
272 #endif
273
274 static spinlock_t *rt_hash_locks;
275 # define rt_hash_lock_addr(slot) &rt_hash_locks[(slot) & (RT_HASH_LOCK_SZ - 1)]
276
277 static __init void rt_hash_lock_init(void)
278 {
279 int i;
280
281 rt_hash_locks = kmalloc(sizeof(spinlock_t) * RT_HASH_LOCK_SZ,
282 GFP_KERNEL);
283 if (!rt_hash_locks)
284 panic("IP: failed to allocate rt_hash_locks\n");
285
286 for (i = 0; i < RT_HASH_LOCK_SZ; i++)
287 spin_lock_init(&rt_hash_locks[i]);
288 }
289 #else
290 # define rt_hash_lock_addr(slot) NULL
291
292 static inline void rt_hash_lock_init(void)
293 {
294 }
295 #endif
296
297 static struct rt_hash_bucket *rt_hash_table __read_mostly;
298 static unsigned rt_hash_mask __read_mostly;
299 static unsigned int rt_hash_log __read_mostly;
300
301 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
302 #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
303
304 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
305 int genid)
306 {
307 return jhash_3words((__force u32)daddr, (__force u32)saddr,
308 idx, genid)
309 & rt_hash_mask;
310 }
311
312 static inline int rt_genid(struct net *net)
313 {
314 return atomic_read(&net->ipv4.rt_genid);
315 }
316
317 #ifdef CONFIG_PROC_FS
318 struct rt_cache_iter_state {
319 struct seq_net_private p;
320 int bucket;
321 int genid;
322 };
323
324 static struct rtable *rt_cache_get_first(struct seq_file *seq)
325 {
326 struct rt_cache_iter_state *st = seq->private;
327 struct rtable *r = NULL;
328
329 for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
330 if (!rcu_access_pointer(rt_hash_table[st->bucket].chain))
331 continue;
332 rcu_read_lock_bh();
333 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
334 while (r) {
335 if (dev_net(r->dst.dev) == seq_file_net(seq) &&
336 r->rt_genid == st->genid)
337 return r;
338 r = rcu_dereference_bh(r->dst.rt_next);
339 }
340 rcu_read_unlock_bh();
341 }
342 return r;
343 }
344
345 static struct rtable *__rt_cache_get_next(struct seq_file *seq,
346 struct rtable *r)
347 {
348 struct rt_cache_iter_state *st = seq->private;
349
350 r = rcu_dereference_bh(r->dst.rt_next);
351 while (!r) {
352 rcu_read_unlock_bh();
353 do {
354 if (--st->bucket < 0)
355 return NULL;
356 } while (!rcu_access_pointer(rt_hash_table[st->bucket].chain));
357 rcu_read_lock_bh();
358 r = rcu_dereference_bh(rt_hash_table[st->bucket].chain);
359 }
360 return r;
361 }
362
363 static struct rtable *rt_cache_get_next(struct seq_file *seq,
364 struct rtable *r)
365 {
366 struct rt_cache_iter_state *st = seq->private;
367 while ((r = __rt_cache_get_next(seq, r)) != NULL) {
368 if (dev_net(r->dst.dev) != seq_file_net(seq))
369 continue;
370 if (r->rt_genid == st->genid)
371 break;
372 }
373 return r;
374 }
375
376 static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
377 {
378 struct rtable *r = rt_cache_get_first(seq);
379
380 if (r)
381 while (pos && (r = rt_cache_get_next(seq, r)))
382 --pos;
383 return pos ? NULL : r;
384 }
385
386 static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
387 {
388 struct rt_cache_iter_state *st = seq->private;
389 if (*pos)
390 return rt_cache_get_idx(seq, *pos - 1);
391 st->genid = rt_genid(seq_file_net(seq));
392 return SEQ_START_TOKEN;
393 }
394
395 static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
396 {
397 struct rtable *r;
398
399 if (v == SEQ_START_TOKEN)
400 r = rt_cache_get_first(seq);
401 else
402 r = rt_cache_get_next(seq, v);
403 ++*pos;
404 return r;
405 }
406
407 static void rt_cache_seq_stop(struct seq_file *seq, void *v)
408 {
409 if (v && v != SEQ_START_TOKEN)
410 rcu_read_unlock_bh();
411 }
412
413 static int rt_cache_seq_show(struct seq_file *seq, void *v)
414 {
415 if (v == SEQ_START_TOKEN)
416 seq_printf(seq, "%-127s\n",
417 "Iface\tDestination\tGateway \tFlags\t\tRefCnt\tUse\t"
418 "Metric\tSource\t\tMTU\tWindow\tIRTT\tTOS\tHHRef\t"
419 "HHUptod\tSpecDst");
420 else {
421 struct rtable *r = v;
422 struct neighbour *n;
423 int len, HHUptod;
424
425 rcu_read_lock();
426 n = dst_get_neighbour_noref(&r->dst);
427 HHUptod = (n && (n->nud_state & NUD_CONNECTED)) ? 1 : 0;
428 rcu_read_unlock();
429
430 seq_printf(seq, "%s\t%08X\t%08X\t%8X\t%d\t%u\t%d\t"
431 "%08X\t%d\t%u\t%u\t%02X\t%d\t%1d\t%08X%n",
432 r->dst.dev ? r->dst.dev->name : "*",
433 (__force u32)r->rt_dst,
434 (__force u32)r->rt_gateway,
435 r->rt_flags, atomic_read(&r->dst.__refcnt),
436 r->dst.__use, 0, (__force u32)r->rt_src,
437 dst_metric_advmss(&r->dst) + 40,
438 dst_metric(&r->dst, RTAX_WINDOW),
439 (int)((dst_metric(&r->dst, RTAX_RTT) >> 3) +
440 dst_metric(&r->dst, RTAX_RTTVAR)),
441 r->rt_key_tos,
442 -1,
443 HHUptod,
444 r->rt_spec_dst, &len);
445
446 seq_printf(seq, "%*s\n", 127 - len, "");
447 }
448 return 0;
449 }
450
451 static const struct seq_operations rt_cache_seq_ops = {
452 .start = rt_cache_seq_start,
453 .next = rt_cache_seq_next,
454 .stop = rt_cache_seq_stop,
455 .show = rt_cache_seq_show,
456 };
457
458 static int rt_cache_seq_open(struct inode *inode, struct file *file)
459 {
460 return seq_open_net(inode, file, &rt_cache_seq_ops,
461 sizeof(struct rt_cache_iter_state));
462 }
463
464 static const struct file_operations rt_cache_seq_fops = {
465 .owner = THIS_MODULE,
466 .open = rt_cache_seq_open,
467 .read = seq_read,
468 .llseek = seq_lseek,
469 .release = seq_release_net,
470 };
471
472
473 static void *rt_cpu_seq_start(struct seq_file *seq, loff_t *pos)
474 {
475 int cpu;
476
477 if (*pos == 0)
478 return SEQ_START_TOKEN;
479
480 for (cpu = *pos-1; cpu < nr_cpu_ids; ++cpu) {
481 if (!cpu_possible(cpu))
482 continue;
483 *pos = cpu+1;
484 return &per_cpu(rt_cache_stat, cpu);
485 }
486 return NULL;
487 }
488
489 static void *rt_cpu_seq_next(struct seq_file *seq, void *v, loff_t *pos)
490 {
491 int cpu;
492
493 for (cpu = *pos; cpu < nr_cpu_ids; ++cpu) {
494 if (!cpu_possible(cpu))
495 continue;
496 *pos = cpu+1;
497 return &per_cpu(rt_cache_stat, cpu);
498 }
499 return NULL;
500
501 }
502
503 static void rt_cpu_seq_stop(struct seq_file *seq, void *v)
504 {
505
506 }
507
508 static int rt_cpu_seq_show(struct seq_file *seq, void *v)
509 {
510 struct rt_cache_stat *st = v;
511
512 if (v == SEQ_START_TOKEN) {
513 seq_printf(seq, "entries in_hit in_slow_tot in_slow_mc in_no_route in_brd in_martian_dst in_martian_src out_hit out_slow_tot out_slow_mc gc_total gc_ignored gc_goal_miss gc_dst_overflow in_hlist_search out_hlist_search\n");
514 return 0;
515 }
516
517 seq_printf(seq,"%08x %08x %08x %08x %08x %08x %08x %08x "
518 " %08x %08x %08x %08x %08x %08x %08x %08x %08x \n",
519 dst_entries_get_slow(&ipv4_dst_ops),
520 st->in_hit,
521 st->in_slow_tot,
522 st->in_slow_mc,
523 st->in_no_route,
524 st->in_brd,
525 st->in_martian_dst,
526 st->in_martian_src,
527
528 st->out_hit,
529 st->out_slow_tot,
530 st->out_slow_mc,
531
532 st->gc_total,
533 st->gc_ignored,
534 st->gc_goal_miss,
535 st->gc_dst_overflow,
536 st->in_hlist_search,
537 st->out_hlist_search
538 );
539 return 0;
540 }
541
542 static const struct seq_operations rt_cpu_seq_ops = {
543 .start = rt_cpu_seq_start,
544 .next = rt_cpu_seq_next,
545 .stop = rt_cpu_seq_stop,
546 .show = rt_cpu_seq_show,
547 };
548
549
550 static int rt_cpu_seq_open(struct inode *inode, struct file *file)
551 {
552 return seq_open(file, &rt_cpu_seq_ops);
553 }
554
555 static const struct file_operations rt_cpu_seq_fops = {
556 .owner = THIS_MODULE,
557 .open = rt_cpu_seq_open,
558 .read = seq_read,
559 .llseek = seq_lseek,
560 .release = seq_release,
561 };
562
563 #ifdef CONFIG_IP_ROUTE_CLASSID
564 static int rt_acct_proc_show(struct seq_file *m, void *v)
565 {
566 struct ip_rt_acct *dst, *src;
567 unsigned int i, j;
568
569 dst = kcalloc(256, sizeof(struct ip_rt_acct), GFP_KERNEL);
570 if (!dst)
571 return -ENOMEM;
572
573 for_each_possible_cpu(i) {
574 src = (struct ip_rt_acct *)per_cpu_ptr(ip_rt_acct, i);
575 for (j = 0; j < 256; j++) {
576 dst[j].o_bytes += src[j].o_bytes;
577 dst[j].o_packets += src[j].o_packets;
578 dst[j].i_bytes += src[j].i_bytes;
579 dst[j].i_packets += src[j].i_packets;
580 }
581 }
582
583 seq_write(m, dst, 256 * sizeof(struct ip_rt_acct));
584 kfree(dst);
585 return 0;
586 }
587
588 static int rt_acct_proc_open(struct inode *inode, struct file *file)
589 {
590 return single_open(file, rt_acct_proc_show, NULL);
591 }
592
593 static const struct file_operations rt_acct_proc_fops = {
594 .owner = THIS_MODULE,
595 .open = rt_acct_proc_open,
596 .read = seq_read,
597 .llseek = seq_lseek,
598 .release = single_release,
599 };
600 #endif
601
602 static int __net_init ip_rt_do_proc_init(struct net *net)
603 {
604 struct proc_dir_entry *pde;
605
606 pde = proc_net_fops_create(net, "rt_cache", S_IRUGO,
607 &rt_cache_seq_fops);
608 if (!pde)
609 goto err1;
610
611 pde = proc_create("rt_cache", S_IRUGO,
612 net->proc_net_stat, &rt_cpu_seq_fops);
613 if (!pde)
614 goto err2;
615
616 #ifdef CONFIG_IP_ROUTE_CLASSID
617 pde = proc_create("rt_acct", 0, net->proc_net, &rt_acct_proc_fops);
618 if (!pde)
619 goto err3;
620 #endif
621 return 0;
622
623 #ifdef CONFIG_IP_ROUTE_CLASSID
624 err3:
625 remove_proc_entry("rt_cache", net->proc_net_stat);
626 #endif
627 err2:
628 remove_proc_entry("rt_cache", net->proc_net);
629 err1:
630 return -ENOMEM;
631 }
632
633 static void __net_exit ip_rt_do_proc_exit(struct net *net)
634 {
635 remove_proc_entry("rt_cache", net->proc_net_stat);
636 remove_proc_entry("rt_cache", net->proc_net);
637 #ifdef CONFIG_IP_ROUTE_CLASSID
638 remove_proc_entry("rt_acct", net->proc_net);
639 #endif
640 }
641
642 static struct pernet_operations ip_rt_proc_ops __net_initdata = {
643 .init = ip_rt_do_proc_init,
644 .exit = ip_rt_do_proc_exit,
645 };
646
647 static int __init ip_rt_proc_init(void)
648 {
649 return register_pernet_subsys(&ip_rt_proc_ops);
650 }
651
652 #else
653 static inline int ip_rt_proc_init(void)
654 {
655 return 0;
656 }
657 #endif /* CONFIG_PROC_FS */
658
659 static inline void rt_free(struct rtable *rt)
660 {
661 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
662 }
663
664 static inline void rt_drop(struct rtable *rt)
665 {
666 ip_rt_put(rt);
667 call_rcu_bh(&rt->dst.rcu_head, dst_rcu_free);
668 }
669
670 static inline int rt_fast_clean(struct rtable *rth)
671 {
672 /* Kill broadcast/multicast entries very aggresively, if they
673 collide in hash table with more useful entries */
674 return (rth->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
675 rt_is_input_route(rth) && rth->dst.rt_next;
676 }
677
678 static inline int rt_valuable(struct rtable *rth)
679 {
680 return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
681 (rth->peer && rth->peer->pmtu_expires);
682 }
683
684 static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
685 {
686 unsigned long age;
687 int ret = 0;
688
689 if (atomic_read(&rth->dst.__refcnt))
690 goto out;
691
692 age = jiffies - rth->dst.lastuse;
693 if ((age <= tmo1 && !rt_fast_clean(rth)) ||
694 (age <= tmo2 && rt_valuable(rth)))
695 goto out;
696 ret = 1;
697 out: return ret;
698 }
699
700 /* Bits of score are:
701 * 31: very valuable
702 * 30: not quite useless
703 * 29..0: usage counter
704 */
705 static inline u32 rt_score(struct rtable *rt)
706 {
707 u32 score = jiffies - rt->dst.lastuse;
708
709 score = ~score & ~(3<<30);
710
711 if (rt_valuable(rt))
712 score |= (1<<31);
713
714 if (rt_is_output_route(rt) ||
715 !(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL)))
716 score |= (1<<30);
717
718 return score;
719 }
720
721 static inline bool rt_caching(const struct net *net)
722 {
723 return net->ipv4.current_rt_cache_rebuild_count <=
724 net->ipv4.sysctl_rt_cache_rebuild_count;
725 }
726
727 static inline bool compare_hash_inputs(const struct rtable *rt1,
728 const struct rtable *rt2)
729 {
730 return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
731 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
732 (rt1->rt_route_iif ^ rt2->rt_route_iif)) == 0);
733 }
734
735 static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
736 {
737 return (((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
738 ((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
739 (rt1->rt_mark ^ rt2->rt_mark) |
740 (rt1->rt_key_tos ^ rt2->rt_key_tos) |
741 (rt1->rt_route_iif ^ rt2->rt_route_iif) |
742 (rt1->rt_oif ^ rt2->rt_oif)) == 0;
743 }
744
745 static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
746 {
747 return net_eq(dev_net(rt1->dst.dev), dev_net(rt2->dst.dev));
748 }
749
750 static inline int rt_is_expired(struct rtable *rth)
751 {
752 return rth->rt_genid != rt_genid(dev_net(rth->dst.dev));
753 }
754
755 /*
756 * Perform a full scan of hash table and free all entries.
757 * Can be called by a softirq or a process.
758 * In the later case, we want to be reschedule if necessary
759 */
760 static void rt_do_flush(struct net *net, int process_context)
761 {
762 unsigned int i;
763 struct rtable *rth, *next;
764
765 for (i = 0; i <= rt_hash_mask; i++) {
766 struct rtable __rcu **pprev;
767 struct rtable *list;
768
769 if (process_context && need_resched())
770 cond_resched();
771 rth = rcu_access_pointer(rt_hash_table[i].chain);
772 if (!rth)
773 continue;
774
775 spin_lock_bh(rt_hash_lock_addr(i));
776
777 list = NULL;
778 pprev = &rt_hash_table[i].chain;
779 rth = rcu_dereference_protected(*pprev,
780 lockdep_is_held(rt_hash_lock_addr(i)));
781
782 while (rth) {
783 next = rcu_dereference_protected(rth->dst.rt_next,
784 lockdep_is_held(rt_hash_lock_addr(i)));
785
786 if (!net ||
787 net_eq(dev_net(rth->dst.dev), net)) {
788 rcu_assign_pointer(*pprev, next);
789 rcu_assign_pointer(rth->dst.rt_next, list);
790 list = rth;
791 } else {
792 pprev = &rth->dst.rt_next;
793 }
794 rth = next;
795 }
796
797 spin_unlock_bh(rt_hash_lock_addr(i));
798
799 for (; list; list = next) {
800 next = rcu_dereference_protected(list->dst.rt_next, 1);
801 rt_free(list);
802 }
803 }
804 }
805
806 /*
807 * While freeing expired entries, we compute average chain length
808 * and standard deviation, using fixed-point arithmetic.
809 * This to have an estimation of rt_chain_length_max
810 * rt_chain_length_max = max(elasticity, AVG + 4*SD)
811 * We use 3 bits for frational part, and 29 (or 61) for magnitude.
812 */
813
814 #define FRACT_BITS 3
815 #define ONE (1UL << FRACT_BITS)
816
817 /*
818 * Given a hash chain and an item in this hash chain,
819 * find if a previous entry has the same hash_inputs
820 * (but differs on tos, mark or oif)
821 * Returns 0 if an alias is found.
822 * Returns ONE if rth has no alias before itself.
823 */
824 static int has_noalias(const struct rtable *head, const struct rtable *rth)
825 {
826 const struct rtable *aux = head;
827
828 while (aux != rth) {
829 if (compare_hash_inputs(aux, rth))
830 return 0;
831 aux = rcu_dereference_protected(aux->dst.rt_next, 1);
832 }
833 return ONE;
834 }
835
836 static void rt_check_expire(void)
837 {
838 static unsigned int rover;
839 unsigned int i = rover, goal;
840 struct rtable *rth;
841 struct rtable __rcu **rthp;
842 unsigned long samples = 0;
843 unsigned long sum = 0, sum2 = 0;
844 unsigned long delta;
845 u64 mult;
846
847 delta = jiffies - expires_ljiffies;
848 expires_ljiffies = jiffies;
849 mult = ((u64)delta) << rt_hash_log;
850 if (ip_rt_gc_timeout > 1)
851 do_div(mult, ip_rt_gc_timeout);
852 goal = (unsigned int)mult;
853 if (goal > rt_hash_mask)
854 goal = rt_hash_mask + 1;
855 for (; goal > 0; goal--) {
856 unsigned long tmo = ip_rt_gc_timeout;
857 unsigned long length;
858
859 i = (i + 1) & rt_hash_mask;
860 rthp = &rt_hash_table[i].chain;
861
862 if (need_resched())
863 cond_resched();
864
865 samples++;
866
867 if (rcu_dereference_raw(*rthp) == NULL)
868 continue;
869 length = 0;
870 spin_lock_bh(rt_hash_lock_addr(i));
871 while ((rth = rcu_dereference_protected(*rthp,
872 lockdep_is_held(rt_hash_lock_addr(i)))) != NULL) {
873 prefetch(rth->dst.rt_next);
874 if (rt_is_expired(rth)) {
875 *rthp = rth->dst.rt_next;
876 rt_free(rth);
877 continue;
878 }
879 if (rth->dst.expires) {
880 /* Entry is expired even if it is in use */
881 if (time_before_eq(jiffies, rth->dst.expires)) {
882 nofree:
883 tmo >>= 1;
884 rthp = &rth->dst.rt_next;
885 /*
886 * We only count entries on
887 * a chain with equal hash inputs once
888 * so that entries for different QOS
889 * levels, and other non-hash input
890 * attributes don't unfairly skew
891 * the length computation
892 */
893 length += has_noalias(rt_hash_table[i].chain, rth);
894 continue;
895 }
896 } else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout))
897 goto nofree;
898
899 /* Cleanup aged off entries. */
900 *rthp = rth->dst.rt_next;
901 rt_free(rth);
902 }
903 spin_unlock_bh(rt_hash_lock_addr(i));
904 sum += length;
905 sum2 += length*length;
906 }
907 if (samples) {
908 unsigned long avg = sum / samples;
909 unsigned long sd = int_sqrt(sum2 / samples - avg*avg);
910 rt_chain_length_max = max_t(unsigned long,
911 ip_rt_gc_elasticity,
912 (avg + 4*sd) >> FRACT_BITS);
913 }
914 rover = i;
915 }
916
917 /*
918 * rt_worker_func() is run in process context.
919 * we call rt_check_expire() to scan part of the hash table
920 */
921 static void rt_worker_func(struct work_struct *work)
922 {
923 rt_check_expire();
924 schedule_delayed_work(&expires_work, ip_rt_gc_interval);
925 }
926
927 /*
928 * Perturbation of rt_genid by a small quantity [1..256]
929 * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
930 * many times (2^24) without giving recent rt_genid.
931 * Jenkins hash is strong enough that litle changes of rt_genid are OK.
932 */
933 static void rt_cache_invalidate(struct net *net)
934 {
935 unsigned char shuffle;
936
937 get_random_bytes(&shuffle, sizeof(shuffle));
938 atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
939 inetpeer_invalidate_tree(AF_INET);
940 }
941
942 /*
943 * delay < 0 : invalidate cache (fast : entries will be deleted later)
944 * delay >= 0 : invalidate & flush cache (can be long)
945 */
946 void rt_cache_flush(struct net *net, int delay)
947 {
948 rt_cache_invalidate(net);
949 if (delay >= 0)
950 rt_do_flush(net, !in_softirq());
951 }
952
953 /* Flush previous cache invalidated entries from the cache */
954 void rt_cache_flush_batch(struct net *net)
955 {
956 rt_do_flush(net, !in_softirq());
957 }
958
959 static void rt_emergency_hash_rebuild(struct net *net)
960 {
961 if (net_ratelimit())
962 printk(KERN_WARNING "Route hash chain too long!\n");
963 rt_cache_invalidate(net);
964 }
965
966 /*
967 Short description of GC goals.
968
969 We want to build algorithm, which will keep routing cache
970 at some equilibrium point, when number of aged off entries
971 is kept approximately equal to newly generated ones.
972
973 Current expiration strength is variable "expire".
974 We try to adjust it dynamically, so that if networking
975 is idle expires is large enough to keep enough of warm entries,
976 and when load increases it reduces to limit cache size.
977 */
978
979 static int rt_garbage_collect(struct dst_ops *ops)
980 {
981 static unsigned long expire = RT_GC_TIMEOUT;
982 static unsigned long last_gc;
983 static int rover;
984 static int equilibrium;
985 struct rtable *rth;
986 struct rtable __rcu **rthp;
987 unsigned long now = jiffies;
988 int goal;
989 int entries = dst_entries_get_fast(&ipv4_dst_ops);
990
991 /*
992 * Garbage collection is pretty expensive,
993 * do not make it too frequently.
994 */
995
996 RT_CACHE_STAT_INC(gc_total);
997
998 if (now - last_gc < ip_rt_gc_min_interval &&
999 entries < ip_rt_max_size) {
1000 RT_CACHE_STAT_INC(gc_ignored);
1001 goto out;
1002 }
1003
1004 entries = dst_entries_get_slow(&ipv4_dst_ops);
1005 /* Calculate number of entries, which we want to expire now. */
1006 goal = entries - (ip_rt_gc_elasticity << rt_hash_log);
1007 if (goal <= 0) {
1008 if (equilibrium < ipv4_dst_ops.gc_thresh)
1009 equilibrium = ipv4_dst_ops.gc_thresh;
1010 goal = entries - equilibrium;
1011 if (goal > 0) {
1012 equilibrium += min_t(unsigned int, goal >> 1, rt_hash_mask + 1);
1013 goal = entries - equilibrium;
1014 }
1015 } else {
1016 /* We are in dangerous area. Try to reduce cache really
1017 * aggressively.
1018 */
1019 goal = max_t(unsigned int, goal >> 1, rt_hash_mask + 1);
1020 equilibrium = entries - goal;
1021 }
1022
1023 if (now - last_gc >= ip_rt_gc_min_interval)
1024 last_gc = now;
1025
1026 if (goal <= 0) {
1027 equilibrium += goal;
1028 goto work_done;
1029 }
1030
1031 do {
1032 int i, k;
1033
1034 for (i = rt_hash_mask, k = rover; i >= 0; i--) {
1035 unsigned long tmo = expire;
1036
1037 k = (k + 1) & rt_hash_mask;
1038 rthp = &rt_hash_table[k].chain;
1039 spin_lock_bh(rt_hash_lock_addr(k));
1040 while ((rth = rcu_dereference_protected(*rthp,
1041 lockdep_is_held(rt_hash_lock_addr(k)))) != NULL) {
1042 if (!rt_is_expired(rth) &&
1043 !rt_may_expire(rth, tmo, expire)) {
1044 tmo >>= 1;
1045 rthp = &rth->dst.rt_next;
1046 continue;
1047 }
1048 *rthp = rth->dst.rt_next;
1049 rt_free(rth);
1050 goal--;
1051 }
1052 spin_unlock_bh(rt_hash_lock_addr(k));
1053 if (goal <= 0)
1054 break;
1055 }
1056 rover = k;
1057
1058 if (goal <= 0)
1059 goto work_done;
1060
1061 /* Goal is not achieved. We stop process if:
1062
1063 - if expire reduced to zero. Otherwise, expire is halfed.
1064 - if table is not full.
1065 - if we are called from interrupt.
1066 - jiffies check is just fallback/debug loop breaker.
1067 We will not spin here for long time in any case.
1068 */
1069
1070 RT_CACHE_STAT_INC(gc_goal_miss);
1071
1072 if (expire == 0)
1073 break;
1074
1075 expire >>= 1;
1076
1077 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
1078 goto out;
1079 } while (!in_softirq() && time_before_eq(jiffies, now));
1080
1081 if (dst_entries_get_fast(&ipv4_dst_ops) < ip_rt_max_size)
1082 goto out;
1083 if (dst_entries_get_slow(&ipv4_dst_ops) < ip_rt_max_size)
1084 goto out;
1085 if (net_ratelimit())
1086 printk(KERN_WARNING "dst cache overflow\n");
1087 RT_CACHE_STAT_INC(gc_dst_overflow);
1088 return 1;
1089
1090 work_done:
1091 expire += ip_rt_gc_min_interval;
1092 if (expire > ip_rt_gc_timeout ||
1093 dst_entries_get_fast(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh ||
1094 dst_entries_get_slow(&ipv4_dst_ops) < ipv4_dst_ops.gc_thresh)
1095 expire = ip_rt_gc_timeout;
1096 out: return 0;
1097 }
1098
1099 /*
1100 * Returns number of entries in a hash chain that have different hash_inputs
1101 */
1102 static int slow_chain_length(const struct rtable *head)
1103 {
1104 int length = 0;
1105 const struct rtable *rth = head;
1106
1107 while (rth) {
1108 length += has_noalias(head, rth);
1109 rth = rcu_dereference_protected(rth->dst.rt_next, 1);
1110 }
1111 return length >> FRACT_BITS;
1112 }
1113
1114 static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, const void *daddr)
1115 {
1116 static const __be32 inaddr_any = 0;
1117 struct net_device *dev = dst->dev;
1118 const __be32 *pkey = daddr;
1119 struct neighbour *n;
1120
1121 if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
1122 pkey = &inaddr_any;
1123
1124 n = __ipv4_neigh_lookup(&arp_tbl, dev, *(__force u32 *)pkey);
1125 if (n)
1126 return n;
1127 return neigh_create(&arp_tbl, pkey, dev);
1128 }
1129
1130 static int rt_bind_neighbour(struct rtable *rt)
1131 {
1132 struct neighbour *n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
1133 if (IS_ERR(n))
1134 return PTR_ERR(n);
1135 dst_set_neighbour(&rt->dst, n);
1136
1137 return 0;
1138 }
1139
1140 static struct rtable *rt_intern_hash(unsigned hash, struct rtable *rt,
1141 struct sk_buff *skb, int ifindex)
1142 {
1143 struct rtable *rth, *cand;
1144 struct rtable __rcu **rthp, **candp;
1145 unsigned long now;
1146 u32 min_score;
1147 int chain_length;
1148 int attempts = !in_softirq();
1149
1150 restart:
1151 chain_length = 0;
1152 min_score = ~(u32)0;
1153 cand = NULL;
1154 candp = NULL;
1155 now = jiffies;
1156
1157 if (!rt_caching(dev_net(rt->dst.dev))) {
1158 /*
1159 * If we're not caching, just tell the caller we
1160 * were successful and don't touch the route. The
1161 * caller hold the sole reference to the cache entry, and
1162 * it will be released when the caller is done with it.
1163 * If we drop it here, the callers have no way to resolve routes
1164 * when we're not caching. Instead, just point *rp at rt, so
1165 * the caller gets a single use out of the route
1166 * Note that we do rt_free on this new route entry, so that
1167 * once its refcount hits zero, we are still able to reap it
1168 * (Thanks Alexey)
1169 * Note: To avoid expensive rcu stuff for this uncached dst,
1170 * we set DST_NOCACHE so that dst_release() can free dst without
1171 * waiting a grace period.
1172 */
1173
1174 rt->dst.flags |= DST_NOCACHE;
1175 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1176 int err = rt_bind_neighbour(rt);
1177 if (err) {
1178 if (net_ratelimit())
1179 printk(KERN_WARNING
1180 "Neighbour table failure & not caching routes.\n");
1181 ip_rt_put(rt);
1182 return ERR_PTR(err);
1183 }
1184 }
1185
1186 goto skip_hashing;
1187 }
1188
1189 rthp = &rt_hash_table[hash].chain;
1190
1191 spin_lock_bh(rt_hash_lock_addr(hash));
1192 while ((rth = rcu_dereference_protected(*rthp,
1193 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1194 if (rt_is_expired(rth)) {
1195 *rthp = rth->dst.rt_next;
1196 rt_free(rth);
1197 continue;
1198 }
1199 if (compare_keys(rth, rt) && compare_netns(rth, rt)) {
1200 /* Put it first */
1201 *rthp = rth->dst.rt_next;
1202 /*
1203 * Since lookup is lockfree, the deletion
1204 * must be visible to another weakly ordered CPU before
1205 * the insertion at the start of the hash chain.
1206 */
1207 rcu_assign_pointer(rth->dst.rt_next,
1208 rt_hash_table[hash].chain);
1209 /*
1210 * Since lookup is lockfree, the update writes
1211 * must be ordered for consistency on SMP.
1212 */
1213 rcu_assign_pointer(rt_hash_table[hash].chain, rth);
1214
1215 dst_use(&rth->dst, now);
1216 spin_unlock_bh(rt_hash_lock_addr(hash));
1217
1218 rt_drop(rt);
1219 if (skb)
1220 skb_dst_set(skb, &rth->dst);
1221 return rth;
1222 }
1223
1224 if (!atomic_read(&rth->dst.__refcnt)) {
1225 u32 score = rt_score(rth);
1226
1227 if (score <= min_score) {
1228 cand = rth;
1229 candp = rthp;
1230 min_score = score;
1231 }
1232 }
1233
1234 chain_length++;
1235
1236 rthp = &rth->dst.rt_next;
1237 }
1238
1239 if (cand) {
1240 /* ip_rt_gc_elasticity used to be average length of chain
1241 * length, when exceeded gc becomes really aggressive.
1242 *
1243 * The second limit is less certain. At the moment it allows
1244 * only 2 entries per bucket. We will see.
1245 */
1246 if (chain_length > ip_rt_gc_elasticity) {
1247 *candp = cand->dst.rt_next;
1248 rt_free(cand);
1249 }
1250 } else {
1251 if (chain_length > rt_chain_length_max &&
1252 slow_chain_length(rt_hash_table[hash].chain) > rt_chain_length_max) {
1253 struct net *net = dev_net(rt->dst.dev);
1254 int num = ++net->ipv4.current_rt_cache_rebuild_count;
1255 if (!rt_caching(net)) {
1256 printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
1257 rt->dst.dev->name, num);
1258 }
1259 rt_emergency_hash_rebuild(net);
1260 spin_unlock_bh(rt_hash_lock_addr(hash));
1261
1262 hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1263 ifindex, rt_genid(net));
1264 goto restart;
1265 }
1266 }
1267
1268 /* Try to bind route to arp only if it is output
1269 route or unicast forwarding path.
1270 */
1271 if (rt->rt_type == RTN_UNICAST || rt_is_output_route(rt)) {
1272 int err = rt_bind_neighbour(rt);
1273 if (err) {
1274 spin_unlock_bh(rt_hash_lock_addr(hash));
1275
1276 if (err != -ENOBUFS) {
1277 rt_drop(rt);
1278 return ERR_PTR(err);
1279 }
1280
1281 /* Neighbour tables are full and nothing
1282 can be released. Try to shrink route cache,
1283 it is most likely it holds some neighbour records.
1284 */
1285 if (attempts-- > 0) {
1286 int saved_elasticity = ip_rt_gc_elasticity;
1287 int saved_int = ip_rt_gc_min_interval;
1288 ip_rt_gc_elasticity = 1;
1289 ip_rt_gc_min_interval = 0;
1290 rt_garbage_collect(&ipv4_dst_ops);
1291 ip_rt_gc_min_interval = saved_int;
1292 ip_rt_gc_elasticity = saved_elasticity;
1293 goto restart;
1294 }
1295
1296 if (net_ratelimit())
1297 printk(KERN_WARNING "ipv4: Neighbour table overflow.\n");
1298 rt_drop(rt);
1299 return ERR_PTR(-ENOBUFS);
1300 }
1301 }
1302
1303 rt->dst.rt_next = rt_hash_table[hash].chain;
1304
1305 /*
1306 * Since lookup is lockfree, we must make sure
1307 * previous writes to rt are committed to memory
1308 * before making rt visible to other CPUS.
1309 */
1310 rcu_assign_pointer(rt_hash_table[hash].chain, rt);
1311
1312 spin_unlock_bh(rt_hash_lock_addr(hash));
1313
1314 skip_hashing:
1315 if (skb)
1316 skb_dst_set(skb, &rt->dst);
1317 return rt;
1318 }
1319
1320 static atomic_t __rt_peer_genid = ATOMIC_INIT(0);
1321
1322 static u32 rt_peer_genid(void)
1323 {
1324 return atomic_read(&__rt_peer_genid);
1325 }
1326
1327 void rt_bind_peer(struct rtable *rt, __be32 daddr, int create)
1328 {
1329 struct inet_peer *peer;
1330
1331 peer = inet_getpeer_v4(daddr, create);
1332
1333 if (peer && cmpxchg(&rt->peer, NULL, peer) != NULL)
1334 inet_putpeer(peer);
1335 else
1336 rt->rt_peer_genid = rt_peer_genid();
1337 }
1338
1339 /*
1340 * Peer allocation may fail only in serious out-of-memory conditions. However
1341 * we still can generate some output.
1342 * Random ID selection looks a bit dangerous because we have no chances to
1343 * select ID being unique in a reasonable period of time.
1344 * But broken packet identifier may be better than no packet at all.
1345 */
1346 static void ip_select_fb_ident(struct iphdr *iph)
1347 {
1348 static DEFINE_SPINLOCK(ip_fb_id_lock);
1349 static u32 ip_fallback_id;
1350 u32 salt;
1351
1352 spin_lock_bh(&ip_fb_id_lock);
1353 salt = secure_ip_id((__force __be32)ip_fallback_id ^ iph->daddr);
1354 iph->id = htons(salt & 0xFFFF);
1355 ip_fallback_id = salt;
1356 spin_unlock_bh(&ip_fb_id_lock);
1357 }
1358
1359 void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
1360 {
1361 struct rtable *rt = (struct rtable *) dst;
1362
1363 if (rt && !(rt->dst.flags & DST_NOPEER)) {
1364 if (rt->peer == NULL)
1365 rt_bind_peer(rt, rt->rt_dst, 1);
1366
1367 /* If peer is attached to destination, it is never detached,
1368 so that we need not to grab a lock to dereference it.
1369 */
1370 if (rt->peer) {
1371 iph->id = htons(inet_getid(rt->peer, more));
1372 return;
1373 }
1374 } else if (!rt)
1375 printk(KERN_DEBUG "rt_bind_peer(0) @%p\n",
1376 __builtin_return_address(0));
1377
1378 ip_select_fb_ident(iph);
1379 }
1380 EXPORT_SYMBOL(__ip_select_ident);
1381
1382 static void rt_del(unsigned hash, struct rtable *rt)
1383 {
1384 struct rtable __rcu **rthp;
1385 struct rtable *aux;
1386
1387 rthp = &rt_hash_table[hash].chain;
1388 spin_lock_bh(rt_hash_lock_addr(hash));
1389 ip_rt_put(rt);
1390 while ((aux = rcu_dereference_protected(*rthp,
1391 lockdep_is_held(rt_hash_lock_addr(hash)))) != NULL) {
1392 if (aux == rt || rt_is_expired(aux)) {
1393 *rthp = aux->dst.rt_next;
1394 rt_free(aux);
1395 continue;
1396 }
1397 rthp = &aux->dst.rt_next;
1398 }
1399 spin_unlock_bh(rt_hash_lock_addr(hash));
1400 }
1401
1402 static void check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
1403 {
1404 struct rtable *rt = (struct rtable *) dst;
1405 __be32 orig_gw = rt->rt_gateway;
1406 struct neighbour *n, *old_n;
1407
1408 dst_confirm(&rt->dst);
1409
1410 rt->rt_gateway = peer->redirect_learned.a4;
1411
1412 n = ipv4_neigh_lookup(&rt->dst, &rt->rt_gateway);
1413 if (IS_ERR(n)) {
1414 rt->rt_gateway = orig_gw;
1415 return;
1416 }
1417 old_n = xchg(&rt->dst._neighbour, n);
1418 if (old_n)
1419 neigh_release(old_n);
1420 if (!(n->nud_state & NUD_VALID)) {
1421 neigh_event_send(n, NULL);
1422 } else {
1423 rt->rt_flags |= RTCF_REDIRECTED;
1424 call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
1425 }
1426 }
1427
1428 /* called in rcu_read_lock() section */
1429 void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
1430 __be32 saddr, struct net_device *dev)
1431 {
1432 int s, i;
1433 struct in_device *in_dev = __in_dev_get_rcu(dev);
1434 __be32 skeys[2] = { saddr, 0 };
1435 int ikeys[2] = { dev->ifindex, 0 };
1436 struct inet_peer *peer;
1437 struct net *net;
1438
1439 if (!in_dev)
1440 return;
1441
1442 net = dev_net(dev);
1443 if (new_gw == old_gw || !IN_DEV_RX_REDIRECTS(in_dev) ||
1444 ipv4_is_multicast(new_gw) || ipv4_is_lbcast(new_gw) ||
1445 ipv4_is_zeronet(new_gw))
1446 goto reject_redirect;
1447
1448 if (!IN_DEV_SHARED_MEDIA(in_dev)) {
1449 if (!inet_addr_onlink(in_dev, new_gw, old_gw))
1450 goto reject_redirect;
1451 if (IN_DEV_SEC_REDIRECTS(in_dev) && ip_fib_check_default(new_gw, dev))
1452 goto reject_redirect;
1453 } else {
1454 if (inet_addr_type(net, new_gw) != RTN_UNICAST)
1455 goto reject_redirect;
1456 }
1457
1458 for (s = 0; s < 2; s++) {
1459 for (i = 0; i < 2; i++) {
1460 unsigned int hash;
1461 struct rtable __rcu **rthp;
1462 struct rtable *rt;
1463
1464 hash = rt_hash(daddr, skeys[s], ikeys[i], rt_genid(net));
1465
1466 rthp = &rt_hash_table[hash].chain;
1467
1468 while ((rt = rcu_dereference(*rthp)) != NULL) {
1469 rthp = &rt->dst.rt_next;
1470
1471 if (rt->rt_key_dst != daddr ||
1472 rt->rt_key_src != skeys[s] ||
1473 rt->rt_oif != ikeys[i] ||
1474 rt_is_input_route(rt) ||
1475 rt_is_expired(rt) ||
1476 !net_eq(dev_net(rt->dst.dev), net) ||
1477 rt->dst.error ||
1478 rt->dst.dev != dev ||
1479 rt->rt_gateway != old_gw)
1480 continue;
1481
1482 if (!rt->peer)
1483 rt_bind_peer(rt, rt->rt_dst, 1);
1484
1485 peer = rt->peer;
1486 if (peer) {
1487 if (peer->redirect_learned.a4 != new_gw) {
1488 peer->redirect_learned.a4 = new_gw;
1489 atomic_inc(&__rt_peer_genid);
1490 }
1491 check_peer_redir(&rt->dst, peer);
1492 }
1493 }
1494 }
1495 }
1496 return;
1497
1498 reject_redirect:
1499 #ifdef CONFIG_IP_ROUTE_VERBOSE
1500 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
1501 printk(KERN_INFO "Redirect from %pI4 on %s about %pI4 ignored.\n"
1502 " Advised path = %pI4 -> %pI4\n",
1503 &old_gw, dev->name, &new_gw,
1504 &saddr, &daddr);
1505 #endif
1506 ;
1507 }
1508
1509 static bool peer_pmtu_expired(struct inet_peer *peer)
1510 {
1511 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1512
1513 return orig &&
1514 time_after_eq(jiffies, orig) &&
1515 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1516 }
1517
1518 static bool peer_pmtu_cleaned(struct inet_peer *peer)
1519 {
1520 unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);
1521
1522 return orig &&
1523 cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
1524 }
1525
1526 static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
1527 {
1528 struct rtable *rt = (struct rtable *)dst;
1529 struct dst_entry *ret = dst;
1530
1531 if (rt) {
1532 if (dst->obsolete > 0) {
1533 ip_rt_put(rt);
1534 ret = NULL;
1535 } else if (rt->rt_flags & RTCF_REDIRECTED) {
1536 unsigned hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
1537 rt->rt_oif,
1538 rt_genid(dev_net(dst->dev)));
1539 rt_del(hash, rt);
1540 ret = NULL;
1541 } else if (rt->peer && peer_pmtu_expired(rt->peer)) {
1542 dst_metric_set(dst, RTAX_MTU, rt->peer->pmtu_orig);
1543 }
1544 }
1545 return ret;
1546 }
1547
1548 /*
1549 * Algorithm:
1550 * 1. The first ip_rt_redirect_number redirects are sent
1551 * with exponential backoff, then we stop sending them at all,
1552 * assuming that the host ignores our redirects.
1553 * 2. If we did not see packets requiring redirects
1554 * during ip_rt_redirect_silence, we assume that the host
1555 * forgot redirected route and start to send redirects again.
1556 *
1557 * This algorithm is much cheaper and more intelligent than dumb load limiting
1558 * in icmp.c.
1559 *
1560 * NOTE. Do not forget to inhibit load limiting for redirects (redundant)
1561 * and "frag. need" (breaks PMTU discovery) in icmp.c.
1562 */
1563
1564 void ip_rt_send_redirect(struct sk_buff *skb)
1565 {
1566 struct rtable *rt = skb_rtable(skb);
1567 struct in_device *in_dev;
1568 struct inet_peer *peer;
1569 int log_martians;
1570
1571 rcu_read_lock();
1572 in_dev = __in_dev_get_rcu(rt->dst.dev);
1573 if (!in_dev || !IN_DEV_TX_REDIRECTS(in_dev)) {
1574 rcu_read_unlock();
1575 return;
1576 }
1577 log_martians = IN_DEV_LOG_MARTIANS(in_dev);
1578 rcu_read_unlock();
1579
1580 if (!rt->peer)
1581 rt_bind_peer(rt, rt->rt_dst, 1);
1582 peer = rt->peer;
1583 if (!peer) {
1584 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1585 return;
1586 }
1587
1588 /* No redirected packets during ip_rt_redirect_silence;
1589 * reset the algorithm.
1590 */
1591 if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
1592 peer->rate_tokens = 0;
1593
1594 /* Too many ignored redirects; do not send anything
1595 * set dst.rate_last to the last seen redirected packet.
1596 */
1597 if (peer->rate_tokens >= ip_rt_redirect_number) {
1598 peer->rate_last = jiffies;
1599 return;
1600 }
1601
1602 /* Check for load limit; set rate_last to the latest sent
1603 * redirect.
1604 */
1605 if (peer->rate_tokens == 0 ||
1606 time_after(jiffies,
1607 (peer->rate_last +
1608 (ip_rt_redirect_load << peer->rate_tokens)))) {
1609 icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
1610 peer->rate_last = jiffies;
1611 ++peer->rate_tokens;
1612 #ifdef CONFIG_IP_ROUTE_VERBOSE
1613 if (log_martians &&
1614 peer->rate_tokens == ip_rt_redirect_number &&
1615 net_ratelimit())
1616 printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
1617 &ip_hdr(skb)->saddr, rt->rt_iif,
1618 &rt->rt_dst, &rt->rt_gateway);
1619 #endif
1620 }
1621 }
1622
1623 static int ip_error(struct sk_buff *skb)
1624 {
1625 struct rtable *rt = skb_rtable(skb);
1626 struct inet_peer *peer;
1627 unsigned long now;
1628 bool send;
1629 int code;
1630
1631 switch (rt->dst.error) {
1632 case EINVAL:
1633 default:
1634 goto out;
1635 case EHOSTUNREACH:
1636 code = ICMP_HOST_UNREACH;
1637 break;
1638 case ENETUNREACH:
1639 code = ICMP_NET_UNREACH;
1640 IP_INC_STATS_BH(dev_net(rt->dst.dev),
1641 IPSTATS_MIB_INNOROUTES);
1642 break;
1643 case EACCES:
1644 code = ICMP_PKT_FILTERED;
1645 break;
1646 }
1647
1648 if (!rt->peer)
1649 rt_bind_peer(rt, rt->rt_dst, 1);
1650 peer = rt->peer;
1651
1652 send = true;
1653 if (peer) {
1654 now = jiffies;
1655 peer->rate_tokens += now - peer->rate_last;
1656 if (peer->rate_tokens > ip_rt_error_burst)
1657 peer->rate_tokens = ip_rt_error_burst;
1658 peer->rate_last = now;
1659 if (peer->rate_tokens >= ip_rt_error_cost)
1660 peer->rate_tokens -= ip_rt_error_cost;
1661 else
1662 send = false;
1663 }
1664 if (send)
1665 icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
1666
1667 out: kfree_skb(skb);
1668 return 0;
1669 }
1670
1671 /*
1672 * The last two values are not from the RFC but
1673 * are needed for AMPRnet AX.25 paths.
1674 */
1675
1676 static const unsigned short mtu_plateau[] =
1677 {32000, 17914, 8166, 4352, 2002, 1492, 576, 296, 216, 128 };
1678
1679 static inline unsigned short guess_mtu(unsigned short old_mtu)
1680 {
1681 int i;
1682
1683 for (i = 0; i < ARRAY_SIZE(mtu_plateau); i++)
1684 if (old_mtu > mtu_plateau[i])
1685 return mtu_plateau[i];
1686 return 68;
1687 }
1688
1689 unsigned short ip_rt_frag_needed(struct net *net, const struct iphdr *iph,
1690 unsigned short new_mtu,
1691 struct net_device *dev)
1692 {
1693 unsigned short old_mtu = ntohs(iph->tot_len);
1694 unsigned short est_mtu = 0;
1695 struct inet_peer *peer;
1696
1697 peer = inet_getpeer_v4(iph->daddr, 1);
1698 if (peer) {
1699 unsigned short mtu = new_mtu;
1700
1701 if (new_mtu < 68 || new_mtu >= old_mtu) {
1702 /* BSD 4.2 derived systems incorrectly adjust
1703 * tot_len by the IP header length, and report
1704 * a zero MTU in the ICMP message.
1705 */
1706 if (mtu == 0 &&
1707 old_mtu >= 68 + (iph->ihl << 2))
1708 old_mtu -= iph->ihl << 2;
1709 mtu = guess_mtu(old_mtu);
1710 }
1711
1712 if (mtu < ip_rt_min_pmtu)
1713 mtu = ip_rt_min_pmtu;
1714 if (!peer->pmtu_expires || mtu < peer->pmtu_learned) {
1715 unsigned long pmtu_expires;
1716
1717 pmtu_expires = jiffies + ip_rt_mtu_expires;
1718 if (!pmtu_expires)
1719 pmtu_expires = 1UL;
1720
1721 est_mtu = mtu;
1722 peer->pmtu_learned = mtu;
1723 peer->pmtu_expires = pmtu_expires;
1724 atomic_inc(&__rt_peer_genid);
1725 }
1726
1727 inet_putpeer(peer);
1728 }
1729 return est_mtu ? : new_mtu;
1730 }
1731
1732 static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
1733 {
1734 unsigned long expires = ACCESS_ONCE(peer->pmtu_expires);
1735
1736 if (!expires)
1737 return;
1738 if (time_before(jiffies, expires)) {
1739 u32 orig_dst_mtu = dst_mtu(dst);
1740 if (peer->pmtu_learned < orig_dst_mtu) {
1741 if (!peer->pmtu_orig)
1742 peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
1743 dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
1744 }
1745 } else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
1746 dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
1747 }
1748
1749 static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
1750 {
1751 struct rtable *rt = (struct rtable *) dst;
1752 struct inet_peer *peer;
1753
1754 dst_confirm(dst);
1755
1756 if (!rt->peer)
1757 rt_bind_peer(rt, rt->rt_dst, 1);
1758 peer = rt->peer;
1759 if (peer) {
1760 unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires);
1761
1762 if (mtu < ip_rt_min_pmtu)
1763 mtu = ip_rt_min_pmtu;
1764 if (!pmtu_expires || mtu < peer->pmtu_learned) {
1765
1766 pmtu_expires = jiffies + ip_rt_mtu_expires;
1767 if (!pmtu_expires)
1768 pmtu_expires = 1UL;
1769
1770 peer->pmtu_learned = mtu;
1771 peer->pmtu_expires = pmtu_expires;
1772
1773 atomic_inc(&__rt_peer_genid);
1774 rt->rt_peer_genid = rt_peer_genid();
1775 }
1776 check_peer_pmtu(dst, peer);
1777 }
1778 }
1779
1780
1781 static void ipv4_validate_peer(struct rtable *rt)
1782 {
1783 if (rt->rt_peer_genid != rt_peer_genid()) {
1784 struct inet_peer *peer;
1785
1786 if (!rt->peer)
1787 rt_bind_peer(rt, rt->rt_dst, 0);
1788
1789 peer = rt->peer;
1790 if (peer) {
1791 check_peer_pmtu(&rt->dst, peer);
1792
1793 if (peer->redirect_learned.a4 &&
1794 peer->redirect_learned.a4 != rt->rt_gateway)
1795 check_peer_redir(&rt->dst, peer);
1796 }
1797
1798 rt->rt_peer_genid = rt_peer_genid();
1799 }
1800 }
1801
1802 static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
1803 {
1804 struct rtable *rt = (struct rtable *) dst;
1805
1806 if (rt_is_expired(rt))
1807 return NULL;
1808 ipv4_validate_peer(rt);
1809 return dst;
1810 }
1811
1812 static void ipv4_dst_destroy(struct dst_entry *dst)
1813 {
1814 struct rtable *rt = (struct rtable *) dst;
1815 struct inet_peer *peer = rt->peer;
1816
1817 if (rt->fi) {
1818 fib_info_put(rt->fi);
1819 rt->fi = NULL;
1820 }
1821 if (peer) {
1822 rt->peer = NULL;
1823 inet_putpeer(peer);
1824 }
1825 }
1826
1827
1828 static void ipv4_link_failure(struct sk_buff *skb)
1829 {
1830 struct rtable *rt;
1831
1832 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);
1833
1834 rt = skb_rtable(skb);
1835 if (rt && rt->peer && peer_pmtu_cleaned(rt->peer))
1836 dst_metric_set(&rt->dst, RTAX_MTU, rt->peer->pmtu_orig);
1837 }
1838
1839 static int ip_rt_bug(struct sk_buff *skb)
1840 {
1841 printk(KERN_DEBUG "ip_rt_bug: %pI4 -> %pI4, %s\n",
1842 &ip_hdr(skb)->saddr, &ip_hdr(skb)->daddr,
1843 skb->dev ? skb->dev->name : "?");
1844 kfree_skb(skb);
1845 WARN_ON(1);
1846 return 0;
1847 }
1848
1849 /*
1850 We do not cache source address of outgoing interface,
1851 because it is used only by IP RR, TS and SRR options,
1852 so that it out of fast path.
1853
1854 BTW remember: "addr" is allowed to be not aligned
1855 in IP options!
1856 */
1857
1858 void ip_rt_get_source(u8 *addr, struct sk_buff *skb, struct rtable *rt)
1859 {
1860 __be32 src;
1861
1862 if (rt_is_output_route(rt))
1863 src = ip_hdr(skb)->saddr;
1864 else {
1865 struct fib_result res;
1866 struct flowi4 fl4;
1867 struct iphdr *iph;
1868
1869 iph = ip_hdr(skb);
1870
1871 memset(&fl4, 0, sizeof(fl4));
1872 fl4.daddr = iph->daddr;
1873 fl4.saddr = iph->saddr;
1874 fl4.flowi4_tos = RT_TOS(iph->tos);
1875 fl4.flowi4_oif = rt->dst.dev->ifindex;
1876 fl4.flowi4_iif = skb->dev->ifindex;
1877 fl4.flowi4_mark = skb->mark;
1878
1879 rcu_read_lock();
1880 if (fib_lookup(dev_net(rt->dst.dev), &fl4, &res) == 0)
1881 src = FIB_RES_PREFSRC(dev_net(rt->dst.dev), res);
1882 else
1883 src = inet_select_addr(rt->dst.dev, rt->rt_gateway,
1884 RT_SCOPE_UNIVERSE);
1885 rcu_read_unlock();
1886 }
1887 memcpy(addr, &src, 4);
1888 }
1889
1890 #ifdef CONFIG_IP_ROUTE_CLASSID
1891 static void set_class_tag(struct rtable *rt, u32 tag)
1892 {
1893 if (!(rt->dst.tclassid & 0xFFFF))
1894 rt->dst.tclassid |= tag & 0xFFFF;
1895 if (!(rt->dst.tclassid & 0xFFFF0000))
1896 rt->dst.tclassid |= tag & 0xFFFF0000;
1897 }
1898 #endif
1899
1900 static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
1901 {
1902 unsigned int advmss = dst_metric_raw(dst, RTAX_ADVMSS);
1903
1904 if (advmss == 0) {
1905 advmss = max_t(unsigned int, dst->dev->mtu - 40,
1906 ip_rt_min_advmss);
1907 if (advmss > 65535 - 40)
1908 advmss = 65535 - 40;
1909 }
1910 return advmss;
1911 }
1912
1913 static unsigned int ipv4_mtu(const struct dst_entry *dst)
1914 {
1915 const struct rtable *rt = (const struct rtable *) dst;
1916 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
1917
1918 if (mtu && rt_is_output_route(rt))
1919 return mtu;
1920
1921 mtu = dst->dev->mtu;
1922
1923 if (unlikely(dst_metric_locked(dst, RTAX_MTU))) {
1924
1925 if (rt->rt_gateway != rt->rt_dst && mtu > 576)
1926 mtu = 576;
1927 }
1928
1929 if (mtu > IP_MAX_MTU)
1930 mtu = IP_MAX_MTU;
1931
1932 return mtu;
1933 }
1934
1935 static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
1936 struct fib_info *fi)
1937 {
1938 struct inet_peer *peer;
1939 int create = 0;
1940
1941 /* If a peer entry exists for this destination, we must hook
1942 * it up in order to get at cached metrics.
1943 */
1944 if (fl4 && (fl4->flowi4_flags & FLOWI_FLAG_PRECOW_METRICS))
1945 create = 1;
1946
1947 rt->peer = peer = inet_getpeer_v4(rt->rt_dst, create);
1948 if (peer) {
1949 rt->rt_peer_genid = rt_peer_genid();
1950 if (inet_metrics_new(peer))
1951 memcpy(peer->metrics, fi->fib_metrics,
1952 sizeof(u32) * RTAX_MAX);
1953 dst_init_metrics(&rt->dst, peer->metrics, false);
1954
1955 check_peer_pmtu(&rt->dst, peer);
1956
1957 if (peer->redirect_learned.a4 &&
1958 peer->redirect_learned.a4 != rt->rt_gateway) {
1959 rt->rt_gateway = peer->redirect_learned.a4;
1960 rt->rt_flags |= RTCF_REDIRECTED;
1961 }
1962 } else {
1963 if (fi->fib_metrics != (u32 *) dst_default_metrics) {
1964 rt->fi = fi;
1965 atomic_inc(&fi->fib_clntref);
1966 }
1967 dst_init_metrics(&rt->dst, fi->fib_metrics, true);
1968 }
1969 }
1970
1971 static void rt_set_nexthop(struct rtable *rt, const struct flowi4 *fl4,
1972 const struct fib_result *res,
1973 struct fib_info *fi, u16 type, u32 itag)
1974 {
1975 struct dst_entry *dst = &rt->dst;
1976
1977 if (fi) {
1978 if (FIB_RES_GW(*res) &&
1979 FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK)
1980 rt->rt_gateway = FIB_RES_GW(*res);
1981 rt_init_metrics(rt, fl4, fi);
1982 #ifdef CONFIG_IP_ROUTE_CLASSID
1983 dst->tclassid = FIB_RES_NH(*res).nh_tclassid;
1984 #endif
1985 }
1986
1987 if (dst_mtu(dst) > IP_MAX_MTU)
1988 dst_metric_set(dst, RTAX_MTU, IP_MAX_MTU);
1989 if (dst_metric_raw(dst, RTAX_ADVMSS) > 65535 - 40)
1990 dst_metric_set(dst, RTAX_ADVMSS, 65535 - 40);
1991
1992 #ifdef CONFIG_IP_ROUTE_CLASSID
1993 #ifdef CONFIG_IP_MULTIPLE_TABLES
1994 set_class_tag(rt, fib_rules_tclass(res));
1995 #endif
1996 set_class_tag(rt, itag);
1997 #endif
1998 }
1999
2000 static struct rtable *rt_dst_alloc(struct net_device *dev,
2001 bool nopolicy, bool noxfrm)
2002 {
2003 return dst_alloc(&ipv4_dst_ops, dev, 1, -1,
2004 DST_HOST |
2005 (nopolicy ? DST_NOPOLICY : 0) |
2006 (noxfrm ? DST_NOXFRM : 0));
2007 }
2008
2009 /* called in rcu_read_lock() section */
2010 static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2011 u8 tos, struct net_device *dev, int our)
2012 {
2013 unsigned int hash;
2014 struct rtable *rth;
2015 __be32 spec_dst;
2016 struct in_device *in_dev = __in_dev_get_rcu(dev);
2017 u32 itag = 0;
2018 int err;
2019
2020 /* Primary sanity checks. */
2021
2022 if (in_dev == NULL)
2023 return -EINVAL;
2024
2025 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2026 ipv4_is_loopback(saddr) || skb->protocol != htons(ETH_P_IP))
2027 goto e_inval;
2028
2029 if (ipv4_is_zeronet(saddr)) {
2030 if (!ipv4_is_local_multicast(daddr))
2031 goto e_inval;
2032 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2033 } else {
2034 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2035 &itag);
2036 if (err < 0)
2037 goto e_err;
2038 }
2039 rth = rt_dst_alloc(init_net.loopback_dev,
2040 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2041 if (!rth)
2042 goto e_nobufs;
2043
2044 #ifdef CONFIG_IP_ROUTE_CLASSID
2045 rth->dst.tclassid = itag;
2046 #endif
2047 rth->dst.output = ip_rt_bug;
2048
2049 rth->rt_key_dst = daddr;
2050 rth->rt_key_src = saddr;
2051 rth->rt_genid = rt_genid(dev_net(dev));
2052 rth->rt_flags = RTCF_MULTICAST;
2053 rth->rt_type = RTN_MULTICAST;
2054 rth->rt_key_tos = tos;
2055 rth->rt_dst = daddr;
2056 rth->rt_src = saddr;
2057 rth->rt_route_iif = dev->ifindex;
2058 rth->rt_iif = dev->ifindex;
2059 rth->rt_oif = 0;
2060 rth->rt_mark = skb->mark;
2061 rth->rt_gateway = daddr;
2062 rth->rt_spec_dst= spec_dst;
2063 rth->rt_peer_genid = 0;
2064 rth->peer = NULL;
2065 rth->fi = NULL;
2066 if (our) {
2067 rth->dst.input= ip_local_deliver;
2068 rth->rt_flags |= RTCF_LOCAL;
2069 }
2070
2071 #ifdef CONFIG_IP_MROUTE
2072 if (!ipv4_is_local_multicast(daddr) && IN_DEV_MFORWARD(in_dev))
2073 rth->dst.input = ip_mr_input;
2074 #endif
2075 RT_CACHE_STAT_INC(in_slow_mc);
2076
2077 hash = rt_hash(daddr, saddr, dev->ifindex, rt_genid(dev_net(dev)));
2078 rth = rt_intern_hash(hash, rth, skb, dev->ifindex);
2079 return IS_ERR(rth) ? PTR_ERR(rth) : 0;
2080
2081 e_nobufs:
2082 return -ENOBUFS;
2083 e_inval:
2084 return -EINVAL;
2085 e_err:
2086 return err;
2087 }
2088
2089
2090 static void ip_handle_martian_source(struct net_device *dev,
2091 struct in_device *in_dev,
2092 struct sk_buff *skb,
2093 __be32 daddr,
2094 __be32 saddr)
2095 {
2096 RT_CACHE_STAT_INC(in_martian_src);
2097 #ifdef CONFIG_IP_ROUTE_VERBOSE
2098 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit()) {
2099 /*
2100 * RFC1812 recommendation, if source is martian,
2101 * the only hint is MAC header.
2102 */
2103 printk(KERN_WARNING "martian source %pI4 from %pI4, on dev %s\n",
2104 &daddr, &saddr, dev->name);
2105 if (dev->hard_header_len && skb_mac_header_was_set(skb)) {
2106 int i;
2107 const unsigned char *p = skb_mac_header(skb);
2108 printk(KERN_WARNING "ll header: ");
2109 for (i = 0; i < dev->hard_header_len; i++, p++) {
2110 printk("%02x", *p);
2111 if (i < (dev->hard_header_len - 1))
2112 printk(":");
2113 }
2114 printk("\n");
2115 }
2116 }
2117 #endif
2118 }
2119
2120 /* called in rcu_read_lock() section */
2121 static int __mkroute_input(struct sk_buff *skb,
2122 const struct fib_result *res,
2123 struct in_device *in_dev,
2124 __be32 daddr, __be32 saddr, u32 tos,
2125 struct rtable **result)
2126 {
2127 struct rtable *rth;
2128 int err;
2129 struct in_device *out_dev;
2130 unsigned int flags = 0;
2131 __be32 spec_dst;
2132 u32 itag;
2133
2134 /* get a working reference to the output device */
2135 out_dev = __in_dev_get_rcu(FIB_RES_DEV(*res));
2136 if (out_dev == NULL) {
2137 if (net_ratelimit())
2138 printk(KERN_CRIT "Bug in ip_route_input" \
2139 "_slow(). Please, report\n");
2140 return -EINVAL;
2141 }
2142
2143
2144 err = fib_validate_source(skb, saddr, daddr, tos, FIB_RES_OIF(*res),
2145 in_dev->dev, &spec_dst, &itag);
2146 if (err < 0) {
2147 ip_handle_martian_source(in_dev->dev, in_dev, skb, daddr,
2148 saddr);
2149
2150 goto cleanup;
2151 }
2152
2153 if (err)
2154 flags |= RTCF_DIRECTSRC;
2155
2156 if (out_dev == in_dev && err &&
2157 (IN_DEV_SHARED_MEDIA(out_dev) ||
2158 inet_addr_onlink(out_dev, saddr, FIB_RES_GW(*res))))
2159 flags |= RTCF_DOREDIRECT;
2160
2161 if (skb->protocol != htons(ETH_P_IP)) {
2162 /* Not IP (i.e. ARP). Do not create route, if it is
2163 * invalid for proxy arp. DNAT routes are always valid.
2164 *
2165 * Proxy arp feature have been extended to allow, ARP
2166 * replies back to the same interface, to support
2167 * Private VLAN switch technologies. See arp.c.
2168 */
2169 if (out_dev == in_dev &&
2170 IN_DEV_PROXY_ARP_PVLAN(in_dev) == 0) {
2171 err = -EINVAL;
2172 goto cleanup;
2173 }
2174 }
2175
2176 rth = rt_dst_alloc(out_dev->dev,
2177 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2178 IN_DEV_CONF_GET(out_dev, NOXFRM));
2179 if (!rth) {
2180 err = -ENOBUFS;
2181 goto cleanup;
2182 }
2183
2184 rth->rt_key_dst = daddr;
2185 rth->rt_key_src = saddr;
2186 rth->rt_genid = rt_genid(dev_net(rth->dst.dev));
2187 rth->rt_flags = flags;
2188 rth->rt_type = res->type;
2189 rth->rt_key_tos = tos;
2190 rth->rt_dst = daddr;
2191 rth->rt_src = saddr;
2192 rth->rt_route_iif = in_dev->dev->ifindex;
2193 rth->rt_iif = in_dev->dev->ifindex;
2194 rth->rt_oif = 0;
2195 rth->rt_mark = skb->mark;
2196 rth->rt_gateway = daddr;
2197 rth->rt_spec_dst= spec_dst;
2198 rth->rt_peer_genid = 0;
2199 rth->peer = NULL;
2200 rth->fi = NULL;
2201
2202 rth->dst.input = ip_forward;
2203 rth->dst.output = ip_output;
2204
2205 rt_set_nexthop(rth, NULL, res, res->fi, res->type, itag);
2206
2207 *result = rth;
2208 err = 0;
2209 cleanup:
2210 return err;
2211 }
2212
2213 static int ip_mkroute_input(struct sk_buff *skb,
2214 struct fib_result *res,
2215 const struct flowi4 *fl4,
2216 struct in_device *in_dev,
2217 __be32 daddr, __be32 saddr, u32 tos)
2218 {
2219 struct rtable* rth = NULL;
2220 int err;
2221 unsigned hash;
2222
2223 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2224 if (res->fi && res->fi->fib_nhs > 1)
2225 fib_select_multipath(res);
2226 #endif
2227
2228 /* create a routing cache entry */
2229 err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth);
2230 if (err)
2231 return err;
2232
2233 /* put it into the cache */
2234 hash = rt_hash(daddr, saddr, fl4->flowi4_iif,
2235 rt_genid(dev_net(rth->dst.dev)));
2236 rth = rt_intern_hash(hash, rth, skb, fl4->flowi4_iif);
2237 if (IS_ERR(rth))
2238 return PTR_ERR(rth);
2239 return 0;
2240 }
2241
2242 /*
2243 * NOTE. We drop all the packets that has local source
2244 * addresses, because every properly looped back packet
2245 * must have correct destination already attached by output routine.
2246 *
2247 * Such approach solves two big problems:
2248 * 1. Not simplex devices are handled properly.
2249 * 2. IP spoofing attempts are filtered with 100% of guarantee.
2250 * called with rcu_read_lock()
2251 */
2252
2253 static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2254 u8 tos, struct net_device *dev)
2255 {
2256 struct fib_result res;
2257 struct in_device *in_dev = __in_dev_get_rcu(dev);
2258 struct flowi4 fl4;
2259 unsigned flags = 0;
2260 u32 itag = 0;
2261 struct rtable * rth;
2262 unsigned hash;
2263 __be32 spec_dst;
2264 int err = -EINVAL;
2265 struct net * net = dev_net(dev);
2266
2267 /* IP on this device is disabled. */
2268
2269 if (!in_dev)
2270 goto out;
2271
2272 /* Check for the most weird martians, which can be not detected
2273 by fib_lookup.
2274 */
2275
2276 if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr) ||
2277 ipv4_is_loopback(saddr))
2278 goto martian_source;
2279
2280 if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0))
2281 goto brd_input;
2282
2283 /* Accept zero addresses only to limited broadcast;
2284 * I even do not know to fix it or not. Waiting for complains :-)
2285 */
2286 if (ipv4_is_zeronet(saddr))
2287 goto martian_source;
2288
2289 if (ipv4_is_zeronet(daddr) || ipv4_is_loopback(daddr))
2290 goto martian_destination;
2291
2292 /*
2293 * Now we are ready to route packet.
2294 */
2295 fl4.flowi4_oif = 0;
2296 fl4.flowi4_iif = dev->ifindex;
2297 fl4.flowi4_mark = skb->mark;
2298 fl4.flowi4_tos = tos;
2299 fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
2300 fl4.daddr = daddr;
2301 fl4.saddr = saddr;
2302 err = fib_lookup(net, &fl4, &res);
2303 if (err != 0) {
2304 if (!IN_DEV_FORWARD(in_dev))
2305 goto e_hostunreach;
2306 goto no_route;
2307 }
2308
2309 RT_CACHE_STAT_INC(in_slow_tot);
2310
2311 if (res.type == RTN_BROADCAST)
2312 goto brd_input;
2313
2314 if (res.type == RTN_LOCAL) {
2315 err = fib_validate_source(skb, saddr, daddr, tos,
2316 net->loopback_dev->ifindex,
2317 dev, &spec_dst, &itag);
2318 if (err < 0)
2319 goto martian_source_keep_err;
2320 if (err)
2321 flags |= RTCF_DIRECTSRC;
2322 spec_dst = daddr;
2323 goto local_input;
2324 }
2325
2326 if (!IN_DEV_FORWARD(in_dev))
2327 goto e_hostunreach;
2328 if (res.type != RTN_UNICAST)
2329 goto martian_destination;
2330
2331 err = ip_mkroute_input(skb, &res, &fl4, in_dev, daddr, saddr, tos);
2332 out: return err;
2333
2334 brd_input:
2335 if (skb->protocol != htons(ETH_P_IP))
2336 goto e_inval;
2337
2338 if (ipv4_is_zeronet(saddr))
2339 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_LINK);
2340 else {
2341 err = fib_validate_source(skb, saddr, 0, tos, 0, dev, &spec_dst,
2342 &itag);
2343 if (err < 0)
2344 goto martian_source_keep_err;
2345 if (err)
2346 flags |= RTCF_DIRECTSRC;
2347 }
2348 flags |= RTCF_BROADCAST;
2349 res.type = RTN_BROADCAST;
2350 RT_CACHE_STAT_INC(in_brd);
2351
2352 local_input:
2353 rth = rt_dst_alloc(net->loopback_dev,
2354 IN_DEV_CONF_GET(in_dev, NOPOLICY), false);
2355 if (!rth)
2356 goto e_nobufs;
2357
2358 rth->dst.input= ip_local_deliver;
2359 rth->dst.output= ip_rt_bug;
2360 #ifdef CONFIG_IP_ROUTE_CLASSID
2361 rth->dst.tclassid = itag;
2362 #endif
2363
2364 rth->rt_key_dst = daddr;
2365 rth->rt_key_src = saddr;
2366 rth->rt_genid = rt_genid(net);
2367 rth->rt_flags = flags|RTCF_LOCAL;
2368 rth->rt_type = res.type;
2369 rth->rt_key_tos = tos;
2370 rth->rt_dst = daddr;
2371 rth->rt_src = saddr;
2372 #ifdef CONFIG_IP_ROUTE_CLASSID
2373 rth->dst.tclassid = itag;
2374 #endif
2375 rth->rt_route_iif = dev->ifindex;
2376 rth->rt_iif = dev->ifindex;
2377 rth->rt_oif = 0;
2378 rth->rt_mark = skb->mark;
2379 rth->rt_gateway = daddr;
2380 rth->rt_spec_dst= spec_dst;
2381 rth->rt_peer_genid = 0;
2382 rth->peer = NULL;
2383 rth->fi = NULL;
2384 if (res.type == RTN_UNREACHABLE) {
2385 rth->dst.input= ip_error;
2386 rth->dst.error= -err;
2387 rth->rt_flags &= ~RTCF_LOCAL;
2388 }
2389 hash = rt_hash(daddr, saddr, fl4.flowi4_iif, rt_genid(net));
2390 rth = rt_intern_hash(hash, rth, skb, fl4.flowi4_iif);
2391 err = 0;
2392 if (IS_ERR(rth))
2393 err = PTR_ERR(rth);
2394 goto out;
2395
2396 no_route:
2397 RT_CACHE_STAT_INC(in_no_route);
2398 spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
2399 res.type = RTN_UNREACHABLE;
2400 if (err == -ESRCH)
2401 err = -ENETUNREACH;
2402 goto local_input;
2403
2404 /*
2405 * Do not cache martian addresses: they should be logged (RFC1812)
2406 */
2407 martian_destination:
2408 RT_CACHE_STAT_INC(in_martian_dst);
2409 #ifdef CONFIG_IP_ROUTE_VERBOSE
2410 if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
2411 printk(KERN_WARNING "martian destination %pI4 from %pI4, dev %s\n",
2412 &daddr, &saddr, dev->name);
2413 #endif
2414
2415 e_hostunreach:
2416 err = -EHOSTUNREACH;
2417 goto out;
2418
2419 e_inval:
2420 err = -EINVAL;
2421 goto out;
2422
2423 e_nobufs:
2424 err = -ENOBUFS;
2425 goto out;
2426
2427 martian_source:
2428 err = -EINVAL;
2429 martian_source_keep_err:
2430 ip_handle_martian_source(dev, in_dev, skb, daddr, saddr);
2431 goto out;
2432 }
2433
2434 int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
2435 u8 tos, struct net_device *dev, bool noref)
2436 {
2437 struct rtable * rth;
2438 unsigned hash;
2439 int iif = dev->ifindex;
2440 struct net *net;
2441 int res;
2442
2443 net = dev_net(dev);
2444
2445 rcu_read_lock();
2446
2447 if (!rt_caching(net))
2448 goto skip_cache;
2449
2450 tos &= IPTOS_RT_MASK;
2451 hash = rt_hash(daddr, saddr, iif, rt_genid(net));
2452
2453 for (rth = rcu_dereference(rt_hash_table[hash].chain); rth;
2454 rth = rcu_dereference(rth->dst.rt_next)) {
2455 if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
2456 ((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
2457 (rth->rt_route_iif ^ iif) |
2458 (rth->rt_key_tos ^ tos)) == 0 &&
2459 rth->rt_mark == skb->mark &&
2460 net_eq(dev_net(rth->dst.dev), net) &&
2461 !rt_is_expired(rth)) {
2462 ipv4_validate_peer(rth);
2463 if (noref) {
2464 dst_use_noref(&rth->dst, jiffies);
2465 skb_dst_set_noref(skb, &rth->dst);
2466 } else {
2467 dst_use(&rth->dst, jiffies);
2468 skb_dst_set(skb, &rth->dst);
2469 }
2470 RT_CACHE_STAT_INC(in_hit);
2471 rcu_read_unlock();
2472 return 0;
2473 }
2474 RT_CACHE_STAT_INC(in_hlist_search);
2475 }
2476
2477 skip_cache:
2478 /* Multicast recognition logic is moved from route cache to here.
2479 The problem was that too many Ethernet cards have broken/missing
2480 hardware multicast filters :-( As result the host on multicasting
2481 network acquires a lot of useless route cache entries, sort of
2482 SDR messages from all the world. Now we try to get rid of them.
2483 Really, provided software IP multicast filter is organized
2484 reasonably (at least, hashed), it does not result in a slowdown
2485 comparing with route cache reject entries.
2486 Note, that multicast routers are not affected, because
2487 route cache entry is created eventually.
2488 */
2489 if (ipv4_is_multicast(daddr)) {
2490 struct in_device *in_dev = __in_dev_get_rcu(dev);
2491
2492 if (in_dev) {
2493 int our = ip_check_mc_rcu(in_dev, daddr, saddr,
2494 ip_hdr(skb)->protocol);
2495 if (our
2496 #ifdef CONFIG_IP_MROUTE
2497 ||
2498 (!ipv4_is_local_multicast(daddr) &&
2499 IN_DEV_MFORWARD(in_dev))
2500 #endif
2501 ) {
2502 int res = ip_route_input_mc(skb, daddr, saddr,
2503 tos, dev, our);
2504 rcu_read_unlock();
2505 return res;
2506 }
2507 }
2508 rcu_read_unlock();
2509 return -EINVAL;
2510 }
2511 res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
2512 rcu_read_unlock();
2513 return res;
2514 }
2515 EXPORT_SYMBOL(ip_route_input_common);
2516
2517 /* called with rcu_read_lock() */
2518 static struct rtable *__mkroute_output(const struct fib_result *res,
2519 const struct flowi4 *fl4,
2520 __be32 orig_daddr, __be32 orig_saddr,
2521 int orig_oif, __u8 orig_rtos,
2522 struct net_device *dev_out,
2523 unsigned int flags)
2524 {
2525 struct fib_info *fi = res->fi;
2526 struct in_device *in_dev;
2527 u16 type = res->type;
2528 struct rtable *rth;
2529
2530 if (ipv4_is_loopback(fl4->saddr) && !(dev_out->flags & IFF_LOOPBACK))
2531 return ERR_PTR(-EINVAL);
2532
2533 if (ipv4_is_lbcast(fl4->daddr))
2534 type = RTN_BROADCAST;
2535 else if (ipv4_is_multicast(fl4->daddr))
2536 type = RTN_MULTICAST;
2537 else if (ipv4_is_zeronet(fl4->daddr))
2538 return ERR_PTR(-EINVAL);
2539
2540 if (dev_out->flags & IFF_LOOPBACK)
2541 flags |= RTCF_LOCAL;
2542
2543 in_dev = __in_dev_get_rcu(dev_out);
2544 if (!in_dev)
2545 return ERR_PTR(-EINVAL);
2546
2547 if (type == RTN_BROADCAST) {
2548 flags |= RTCF_BROADCAST | RTCF_LOCAL;
2549 fi = NULL;
2550 } else if (type == RTN_MULTICAST) {
2551 flags |= RTCF_MULTICAST | RTCF_LOCAL;
2552 if (!ip_check_mc_rcu(in_dev, fl4->daddr, fl4->saddr,
2553 fl4->flowi4_proto))
2554 flags &= ~RTCF_LOCAL;
2555 /* If multicast route do not exist use
2556 * default one, but do not gateway in this case.
2557 * Yes, it is hack.
2558 */
2559 if (fi && res->prefixlen < 4)
2560 fi = NULL;
2561 }
2562
2563 rth = rt_dst_alloc(dev_out,
2564 IN_DEV_CONF_GET(in_dev, NOPOLICY),
2565 IN_DEV_CONF_GET(in_dev, NOXFRM));
2566 if (!rth)
2567 return ERR_PTR(-ENOBUFS);
2568
2569 rth->dst.output = ip_output;
2570
2571 rth->rt_key_dst = orig_daddr;
2572 rth->rt_key_src = orig_saddr;
2573 rth->rt_genid = rt_genid(dev_net(dev_out));
2574 rth->rt_flags = flags;
2575 rth->rt_type = type;
2576 rth->rt_key_tos = orig_rtos;
2577 rth->rt_dst = fl4->daddr;
2578 rth->rt_src = fl4->saddr;
2579 rth->rt_route_iif = 0;
2580 rth->rt_iif = orig_oif ? : dev_out->ifindex;
2581 rth->rt_oif = orig_oif;
2582 rth->rt_mark = fl4->flowi4_mark;
2583 rth->rt_gateway = fl4->daddr;
2584 rth->rt_spec_dst= fl4->saddr;
2585 rth->rt_peer_genid = 0;
2586 rth->peer = NULL;
2587 rth->fi = NULL;
2588
2589 RT_CACHE_STAT_INC(out_slow_tot);
2590
2591 if (flags & RTCF_LOCAL) {
2592 rth->dst.input = ip_local_deliver;
2593 rth->rt_spec_dst = fl4->daddr;
2594 }
2595 if (flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
2596 rth->rt_spec_dst = fl4->saddr;
2597 if (flags & RTCF_LOCAL &&
2598 !(dev_out->flags & IFF_LOOPBACK)) {
2599 rth->dst.output = ip_mc_output;
2600 RT_CACHE_STAT_INC(out_slow_mc);
2601 }
2602 #ifdef CONFIG_IP_MROUTE
2603 if (type == RTN_MULTICAST) {
2604 if (IN_DEV_MFORWARD(in_dev) &&
2605 !ipv4_is_local_multicast(fl4->daddr)) {
2606 rth->dst.input = ip_mr_input;
2607 rth->dst.output = ip_mc_output;
2608 }
2609 }
2610 #endif
2611 }
2612
2613 rt_set_nexthop(rth, fl4, res, fi, type, 0);
2614
2615 return rth;
2616 }
2617
2618 /*
2619 * Major route resolver routine.
2620 * called with rcu_read_lock();
2621 */
2622
2623 static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
2624 {
2625 struct net_device *dev_out = NULL;
2626 __u8 tos = RT_FL_TOS(fl4);
2627 unsigned int flags = 0;
2628 struct fib_result res;
2629 struct rtable *rth;
2630 __be32 orig_daddr;
2631 __be32 orig_saddr;
2632 int orig_oif;
2633
2634 res.fi = NULL;
2635 #ifdef CONFIG_IP_MULTIPLE_TABLES
2636 res.r = NULL;
2637 #endif
2638
2639 orig_daddr = fl4->daddr;
2640 orig_saddr = fl4->saddr;
2641 orig_oif = fl4->flowi4_oif;
2642
2643 fl4->flowi4_iif = net->loopback_dev->ifindex;
2644 fl4->flowi4_tos = tos & IPTOS_RT_MASK;
2645 fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
2646 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
2647
2648 rcu_read_lock();
2649 if (fl4->saddr) {
2650 rth = ERR_PTR(-EINVAL);
2651 if (ipv4_is_multicast(fl4->saddr) ||
2652 ipv4_is_lbcast(fl4->saddr) ||
2653 ipv4_is_zeronet(fl4->saddr))
2654 goto out;
2655
2656 /* I removed check for oif == dev_out->oif here.
2657 It was wrong for two reasons:
2658 1. ip_dev_find(net, saddr) can return wrong iface, if saddr
2659 is assigned to multiple interfaces.
2660 2. Moreover, we are allowed to send packets with saddr
2661 of another iface. --ANK
2662 */
2663
2664 if (fl4->flowi4_oif == 0 &&
2665 (ipv4_is_multicast(fl4->daddr) ||
2666 ipv4_is_lbcast(fl4->daddr))) {
2667 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2668 dev_out = __ip_dev_find(net, fl4->saddr, false);
2669 if (dev_out == NULL)
2670 goto out;
2671
2672 /* Special hack: user can direct multicasts
2673 and limited broadcast via necessary interface
2674 without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
2675 This hack is not just for fun, it allows
2676 vic,vat and friends to work.
2677 They bind socket to loopback, set ttl to zero
2678 and expect that it will work.
2679 From the viewpoint of routing cache they are broken,
2680 because we are not allowed to build multicast path
2681 with loopback source addr (look, routing cache
2682 cannot know, that ttl is zero, so that packet
2683 will not leave this host and route is valid).
2684 Luckily, this hack is good workaround.
2685 */
2686
2687 fl4->flowi4_oif = dev_out->ifindex;
2688 goto make_route;
2689 }
2690
2691 if (!(fl4->flowi4_flags & FLOWI_FLAG_ANYSRC)) {
2692 /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
2693 if (!__ip_dev_find(net, fl4->saddr, false))
2694 goto out;
2695 }
2696 }
2697
2698
2699 if (fl4->flowi4_oif) {
2700 dev_out = dev_get_by_index_rcu(net, fl4->flowi4_oif);
2701 rth = ERR_PTR(-ENODEV);
2702 if (dev_out == NULL)
2703 goto out;
2704
2705 /* RACE: Check return value of inet_select_addr instead. */
2706 if (!(dev_out->flags & IFF_UP) || !__in_dev_get_rcu(dev_out)) {
2707 rth = ERR_PTR(-ENETUNREACH);
2708 goto out;
2709 }
2710 if (ipv4_is_local_multicast(fl4->daddr) ||
2711 ipv4_is_lbcast(fl4->daddr)) {
2712 if (!fl4->saddr)
2713 fl4->saddr = inet_select_addr(dev_out, 0,
2714 RT_SCOPE_LINK);
2715 goto make_route;
2716 }
2717 if (fl4->saddr) {
2718 if (ipv4_is_multicast(fl4->daddr))
2719 fl4->saddr = inet_select_addr(dev_out, 0,
2720 fl4->flowi4_scope);
2721 else if (!fl4->daddr)
2722 fl4->saddr = inet_select_addr(dev_out, 0,
2723 RT_SCOPE_HOST);
2724 }
2725 }
2726
2727 if (!fl4->daddr) {
2728 fl4->daddr = fl4->saddr;
2729 if (!fl4->daddr)
2730 fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
2731 dev_out = net->loopback_dev;
2732 fl4->flowi4_oif = net->loopback_dev->ifindex;
2733 res.type = RTN_LOCAL;
2734 flags |= RTCF_LOCAL;
2735 goto make_route;
2736 }
2737
2738 if (fib_lookup(net, fl4, &res)) {
2739 res.fi = NULL;
2740 if (fl4->flowi4_oif) {
2741 /* Apparently, routing tables are wrong. Assume,
2742 that the destination is on link.
2743
2744 WHY? DW.
2745 Because we are allowed to send to iface
2746 even if it has NO routes and NO assigned
2747 addresses. When oif is specified, routing
2748 tables are looked up with only one purpose:
2749 to catch if destination is gatewayed, rather than
2750 direct. Moreover, if MSG_DONTROUTE is set,
2751 we send packet, ignoring both routing tables
2752 and ifaddr state. --ANK
2753
2754
2755 We could make it even if oif is unknown,
2756 likely IPv6, but we do not.
2757 */
2758
2759 if (fl4->saddr == 0)
2760 fl4->saddr = inet_select_addr(dev_out, 0,
2761 RT_SCOPE_LINK);
2762 res.type = RTN_UNICAST;
2763 goto make_route;
2764 }
2765 rth = ERR_PTR(-ENETUNREACH);
2766 goto out;
2767 }
2768
2769 if (res.type == RTN_LOCAL) {
2770 if (!fl4->saddr) {
2771 if (res.fi->fib_prefsrc)
2772 fl4->saddr = res.fi->fib_prefsrc;
2773 else
2774 fl4->saddr = fl4->daddr;
2775 }
2776 dev_out = net->loopback_dev;
2777 fl4->flowi4_oif = dev_out->ifindex;
2778 res.fi = NULL;
2779 flags |= RTCF_LOCAL;
2780 goto make_route;
2781 }
2782
2783 #ifdef CONFIG_IP_ROUTE_MULTIPATH
2784 if (res.fi->fib_nhs > 1 && fl4->flowi4_oif == 0)
2785 fib_select_multipath(&res);
2786 else
2787 #endif
2788 if (!res.prefixlen &&
2789 res.table->tb_num_default > 1 &&
2790 res.type == RTN_UNICAST && !fl4->flowi4_oif)
2791 fib_select_default(&res);
2792
2793 if (!fl4->saddr)
2794 fl4->saddr = FIB_RES_PREFSRC(net, res);
2795
2796 dev_out = FIB_RES_DEV(res);
2797 fl4->flowi4_oif = dev_out->ifindex;
2798
2799
2800 make_route:
2801 rth = __mkroute_output(&res, fl4, orig_daddr, orig_saddr, orig_oif,
2802 tos, dev_out, flags);
2803 if (!IS_ERR(rth)) {
2804 unsigned int hash;
2805
2806 hash = rt_hash(orig_daddr, orig_saddr, orig_oif,
2807 rt_genid(dev_net(dev_out)));
2808 rth = rt_intern_hash(hash, rth, NULL, orig_oif);
2809 }
2810
2811 out:
2812 rcu_read_unlock();
2813 return rth;
2814 }
2815
2816 struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
2817 {
2818 struct rtable *rth;
2819 unsigned int hash;
2820
2821 if (!rt_caching(net))
2822 goto slow_output;
2823
2824 hash = rt_hash(flp4->daddr, flp4->saddr, flp4->flowi4_oif, rt_genid(net));
2825
2826 rcu_read_lock_bh();
2827 for (rth = rcu_dereference_bh(rt_hash_table[hash].chain); rth;
2828 rth = rcu_dereference_bh(rth->dst.rt_next)) {
2829 if (rth->rt_key_dst == flp4->daddr &&
2830 rth->rt_key_src == flp4->saddr &&
2831 rt_is_output_route(rth) &&
2832 rth->rt_oif == flp4->flowi4_oif &&
2833 rth->rt_mark == flp4->flowi4_mark &&
2834 !((rth->rt_key_tos ^ flp4->flowi4_tos) &
2835 (IPTOS_RT_MASK | RTO_ONLINK)) &&
2836 net_eq(dev_net(rth->dst.dev), net) &&
2837 !rt_is_expired(rth)) {
2838 ipv4_validate_peer(rth);
2839 dst_use(&rth->dst, jiffies);
2840 RT_CACHE_STAT_INC(out_hit);
2841 rcu_read_unlock_bh();
2842 if (!flp4->saddr)
2843 flp4->saddr = rth->rt_src;
2844 if (!flp4->daddr)
2845 flp4->daddr = rth->rt_dst;
2846 return rth;
2847 }
2848 RT_CACHE_STAT_INC(out_hlist_search);
2849 }
2850 rcu_read_unlock_bh();
2851
2852 slow_output:
2853 return ip_route_output_slow(net, flp4);
2854 }
2855 EXPORT_SYMBOL_GPL(__ip_route_output_key);
2856
2857 static struct dst_entry *ipv4_blackhole_dst_check(struct dst_entry *dst, u32 cookie)
2858 {
2859 return NULL;
2860 }
2861
2862 static unsigned int ipv4_blackhole_mtu(const struct dst_entry *dst)
2863 {
2864 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
2865
2866 return mtu ? : dst->dev->mtu;
2867 }
2868
2869 static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu)
2870 {
2871 }
2872
2873 static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst,
2874 unsigned long old)
2875 {
2876 return NULL;
2877 }
2878
2879 static struct dst_ops ipv4_dst_blackhole_ops = {
2880 .family = AF_INET,
2881 .protocol = cpu_to_be16(ETH_P_IP),
2882 .destroy = ipv4_dst_destroy,
2883 .check = ipv4_blackhole_dst_check,
2884 .mtu = ipv4_blackhole_mtu,
2885 .default_advmss = ipv4_default_advmss,
2886 .update_pmtu = ipv4_rt_blackhole_update_pmtu,
2887 .cow_metrics = ipv4_rt_blackhole_cow_metrics,
2888 .neigh_lookup = ipv4_neigh_lookup,
2889 };
2890
2891 struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig)
2892 {
2893 struct rtable *rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, 0, 0);
2894 struct rtable *ort = (struct rtable *) dst_orig;
2895
2896 if (rt) {
2897 struct dst_entry *new = &rt->dst;
2898
2899 new->__use = 1;
2900 new->input = dst_discard;
2901 new->output = dst_discard;
2902 dst_copy_metrics(new, &ort->dst);
2903
2904 new->dev = ort->dst.dev;
2905 if (new->dev)
2906 dev_hold(new->dev);
2907
2908 rt->rt_key_dst = ort->rt_key_dst;
2909 rt->rt_key_src = ort->rt_key_src;
2910 rt->rt_key_tos = ort->rt_key_tos;
2911 rt->rt_route_iif = ort->rt_route_iif;
2912 rt->rt_iif = ort->rt_iif;
2913 rt->rt_oif = ort->rt_oif;
2914 rt->rt_mark = ort->rt_mark;
2915
2916 rt->rt_genid = rt_genid(net);
2917 rt->rt_flags = ort->rt_flags;
2918 rt->rt_type = ort->rt_type;
2919 rt->rt_dst = ort->rt_dst;
2920 rt->rt_src = ort->rt_src;
2921 rt->rt_gateway = ort->rt_gateway;
2922 rt->rt_spec_dst = ort->rt_spec_dst;
2923 rt->peer = ort->peer;
2924 if (rt->peer)
2925 atomic_inc(&rt->peer->refcnt);
2926 rt->fi = ort->fi;
2927 if (rt->fi)
2928 atomic_inc(&rt->fi->fib_clntref);
2929
2930 dst_free(new);
2931 }
2932
2933 dst_release(dst_orig);
2934
2935 return rt ? &rt->dst : ERR_PTR(-ENOMEM);
2936 }
2937
2938 struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4,
2939 struct sock *sk)
2940 {
2941 struct rtable *rt = __ip_route_output_key(net, flp4);
2942
2943 if (IS_ERR(rt))
2944 return rt;
2945
2946 if (flp4->flowi4_proto)
2947 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
2948 flowi4_to_flowi(flp4),
2949 sk, 0);
2950
2951 return rt;
2952 }
2953 EXPORT_SYMBOL_GPL(ip_route_output_flow);
2954
2955 static int rt_fill_info(struct net *net,
2956 struct sk_buff *skb, u32 pid, u32 seq, int event,
2957 int nowait, unsigned int flags)
2958 {
2959 struct rtable *rt = skb_rtable(skb);
2960 struct rtmsg *r;
2961 struct nlmsghdr *nlh;
2962 unsigned long expires = 0;
2963 const struct inet_peer *peer = rt->peer;
2964 u32 id = 0, ts = 0, tsage = 0, error;
2965
2966 nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags);
2967 if (nlh == NULL)
2968 return -EMSGSIZE;
2969
2970 r = nlmsg_data(nlh);
2971 r->rtm_family = AF_INET;
2972 r->rtm_dst_len = 32;
2973 r->rtm_src_len = 0;
2974 r->rtm_tos = rt->rt_key_tos;
2975 r->rtm_table = RT_TABLE_MAIN;
2976 NLA_PUT_U32(skb, RTA_TABLE, RT_TABLE_MAIN);
2977 r->rtm_type = rt->rt_type;
2978 r->rtm_scope = RT_SCOPE_UNIVERSE;
2979 r->rtm_protocol = RTPROT_UNSPEC;
2980 r->rtm_flags = (rt->rt_flags & ~0xFFFF) | RTM_F_CLONED;
2981 if (rt->rt_flags & RTCF_NOTIFY)
2982 r->rtm_flags |= RTM_F_NOTIFY;
2983
2984 NLA_PUT_BE32(skb, RTA_DST, rt->rt_dst);
2985
2986 if (rt->rt_key_src) {
2987 r->rtm_src_len = 32;
2988 NLA_PUT_BE32(skb, RTA_SRC, rt->rt_key_src);
2989 }
2990 if (rt->dst.dev)
2991 NLA_PUT_U32(skb, RTA_OIF, rt->dst.dev->ifindex);
2992 #ifdef CONFIG_IP_ROUTE_CLASSID
2993 if (rt->dst.tclassid)
2994 NLA_PUT_U32(skb, RTA_FLOW, rt->dst.tclassid);
2995 #endif
2996 if (rt_is_input_route(rt))
2997 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_spec_dst);
2998 else if (rt->rt_src != rt->rt_key_src)
2999 NLA_PUT_BE32(skb, RTA_PREFSRC, rt->rt_src);
3000
3001 if (rt->rt_dst != rt->rt_gateway)
3002 NLA_PUT_BE32(skb, RTA_GATEWAY, rt->rt_gateway);
3003
3004 if (rtnetlink_put_metrics(skb, dst_metrics_ptr(&rt->dst)) < 0)
3005 goto nla_put_failure;
3006
3007 if (rt->rt_mark)
3008 NLA_PUT_BE32(skb, RTA_MARK, rt->rt_mark);
3009
3010 error = rt->dst.error;
3011 if (peer) {
3012 inet_peer_refcheck(rt->peer);
3013 id = atomic_read(&peer->ip_id_count) & 0xffff;
3014 if (peer->tcp_ts_stamp) {
3015 ts = peer->tcp_ts;
3016 tsage = get_seconds() - peer->tcp_ts_stamp;
3017 }
3018 expires = ACCESS_ONCE(peer->pmtu_expires);
3019 if (expires) {
3020 if (time_before(jiffies, expires))
3021 expires -= jiffies;
3022 else
3023 expires = 0;
3024 }
3025 }
3026
3027 if (rt_is_input_route(rt)) {
3028 #ifdef CONFIG_IP_MROUTE
3029 __be32 dst = rt->rt_dst;
3030
3031 if (ipv4_is_multicast(dst) && !ipv4_is_local_multicast(dst) &&
3032 IPV4_DEVCONF_ALL(net, MC_FORWARDING)) {
3033 int err = ipmr_get_route(net, skb,
3034 rt->rt_src, rt->rt_dst,
3035 r, nowait);
3036 if (err <= 0) {
3037 if (!nowait) {
3038 if (err == 0)
3039 return 0;
3040 goto nla_put_failure;
3041 } else {
3042 if (err == -EMSGSIZE)
3043 goto nla_put_failure;
3044 error = err;
3045 }
3046 }
3047 } else
3048 #endif
3049 NLA_PUT_U32(skb, RTA_IIF, rt->rt_iif);
3050 }
3051
3052 if (rtnl_put_cacheinfo(skb, &rt->dst, id, ts, tsage,
3053 expires, error) < 0)
3054 goto nla_put_failure;
3055
3056 return nlmsg_end(skb, nlh);
3057
3058 nla_put_failure:
3059 nlmsg_cancel(skb, nlh);
3060 return -EMSGSIZE;
3061 }
3062
3063 static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
3064 {
3065 struct net *net = sock_net(in_skb->sk);
3066 struct rtmsg *rtm;
3067 struct nlattr *tb[RTA_MAX+1];
3068 struct rtable *rt = NULL;
3069 __be32 dst = 0;
3070 __be32 src = 0;
3071 u32 iif;
3072 int err;
3073 int mark;
3074 struct sk_buff *skb;
3075
3076 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv4_policy);
3077 if (err < 0)
3078 goto errout;
3079
3080 rtm = nlmsg_data(nlh);
3081
3082 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
3083 if (skb == NULL) {
3084 err = -ENOBUFS;
3085 goto errout;
3086 }
3087
3088 /* Reserve room for dummy headers, this skb can pass
3089 through good chunk of routing engine.
3090 */
3091 skb_reset_mac_header(skb);
3092 skb_reset_network_header(skb);
3093
3094 /* Bugfix: need to give ip_route_input enough of an IP header to not gag. */
3095 ip_hdr(skb)->protocol = IPPROTO_ICMP;
3096 skb_reserve(skb, MAX_HEADER + sizeof(struct iphdr));
3097
3098 src = tb[RTA_SRC] ? nla_get_be32(tb[RTA_SRC]) : 0;
3099 dst = tb[RTA_DST] ? nla_get_be32(tb[RTA_DST]) : 0;
3100 iif = tb[RTA_IIF] ? nla_get_u32(tb[RTA_IIF]) : 0;
3101 mark = tb[RTA_MARK] ? nla_get_u32(tb[RTA_MARK]) : 0;
3102
3103 if (iif) {
3104 struct net_device *dev;
3105
3106 dev = __dev_get_by_index(net, iif);
3107 if (dev == NULL) {
3108 err = -ENODEV;
3109 goto errout_free;
3110 }
3111
3112 skb->protocol = htons(ETH_P_IP);
3113 skb->dev = dev;
3114 skb->mark = mark;
3115 local_bh_disable();
3116 err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev);
3117 local_bh_enable();
3118
3119 rt = skb_rtable(skb);
3120 if (err == 0 && rt->dst.error)
3121 err = -rt->dst.error;
3122 } else {
3123 struct flowi4 fl4 = {
3124 .daddr = dst,
3125 .saddr = src,
3126 .flowi4_tos = rtm->rtm_tos,
3127 .flowi4_oif = tb[RTA_OIF] ? nla_get_u32(tb[RTA_OIF]) : 0,
3128 .flowi4_mark = mark,
3129 };
3130 rt = ip_route_output_key(net, &fl4);
3131
3132 err = 0;
3133 if (IS_ERR(rt))
3134 err = PTR_ERR(rt);
3135 }
3136
3137 if (err)
3138 goto errout_free;
3139
3140 skb_dst_set(skb, &rt->dst);
3141 if (rtm->rtm_flags & RTM_F_NOTIFY)
3142 rt->rt_flags |= RTCF_NOTIFY;
3143
3144 err = rt_fill_info(net, skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
3145 RTM_NEWROUTE, 0, 0);
3146 if (err <= 0)
3147 goto errout_free;
3148
3149 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid);
3150 errout:
3151 return err;
3152
3153 errout_free:
3154 kfree_skb(skb);
3155 goto errout;
3156 }
3157
3158 int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
3159 {
3160 struct rtable *rt;
3161 int h, s_h;
3162 int idx, s_idx;
3163 struct net *net;
3164
3165 net = sock_net(skb->sk);
3166
3167 s_h = cb->args[0];
3168 if (s_h < 0)
3169 s_h = 0;
3170 s_idx = idx = cb->args[1];
3171 for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
3172 if (!rt_hash_table[h].chain)
3173 continue;
3174 rcu_read_lock_bh();
3175 for (rt = rcu_dereference_bh(rt_hash_table[h].chain), idx = 0; rt;
3176 rt = rcu_dereference_bh(rt->dst.rt_next), idx++) {
3177 if (!net_eq(dev_net(rt->dst.dev), net) || idx < s_idx)
3178 continue;
3179 if (rt_is_expired(rt))
3180 continue;
3181 skb_dst_set_noref(skb, &rt->dst);
3182 if (rt_fill_info(net, skb, NETLINK_CB(cb->skb).pid,
3183 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
3184 1, NLM_F_MULTI) <= 0) {
3185 skb_dst_drop(skb);
3186 rcu_read_unlock_bh();
3187 goto done;
3188 }
3189 skb_dst_drop(skb);
3190 }
3191 rcu_read_unlock_bh();
3192 }
3193
3194 done:
3195 cb->args[0] = h;
3196 cb->args[1] = idx;
3197 return skb->len;
3198 }
3199
3200 void ip_rt_multicast_event(struct in_device *in_dev)
3201 {
3202 rt_cache_flush(dev_net(in_dev->dev), 0);
3203 }
3204
3205 #ifdef CONFIG_SYSCTL
3206 static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write,
3207 void __user *buffer,
3208 size_t *lenp, loff_t *ppos)
3209 {
3210 if (write) {
3211 int flush_delay;
3212 ctl_table ctl;
3213 struct net *net;
3214
3215 memcpy(&ctl, __ctl, sizeof(ctl));
3216 ctl.data = &flush_delay;
3217 proc_dointvec(&ctl, write, buffer, lenp, ppos);
3218
3219 net = (struct net *)__ctl->extra1;
3220 rt_cache_flush(net, flush_delay);
3221 return 0;
3222 }
3223
3224 return -EINVAL;
3225 }
3226
3227 static ctl_table ipv4_route_table[] = {
3228 {
3229 .procname = "gc_thresh",
3230 .data = &ipv4_dst_ops.gc_thresh,
3231 .maxlen = sizeof(int),
3232 .mode = 0644,
3233 .proc_handler = proc_dointvec,
3234 },
3235 {
3236 .procname = "max_size",
3237 .data = &ip_rt_max_size,
3238 .maxlen = sizeof(int),
3239 .mode = 0644,
3240 .proc_handler = proc_dointvec,
3241 },
3242 {
3243 /* Deprecated. Use gc_min_interval_ms */
3244
3245 .procname = "gc_min_interval",
3246 .data = &ip_rt_gc_min_interval,
3247 .maxlen = sizeof(int),
3248 .mode = 0644,
3249 .proc_handler = proc_dointvec_jiffies,
3250 },
3251 {
3252 .procname = "gc_min_interval_ms",
3253 .data = &ip_rt_gc_min_interval,
3254 .maxlen = sizeof(int),
3255 .mode = 0644,
3256 .proc_handler = proc_dointvec_ms_jiffies,
3257 },
3258 {
3259 .procname = "gc_timeout",
3260 .data = &ip_rt_gc_timeout,
3261 .maxlen = sizeof(int),
3262 .mode = 0644,
3263 .proc_handler = proc_dointvec_jiffies,
3264 },
3265 {
3266 .procname = "gc_interval",
3267 .data = &ip_rt_gc_interval,
3268 .maxlen = sizeof(int),
3269 .mode = 0644,
3270 .proc_handler = proc_dointvec_jiffies,
3271 },
3272 {
3273 .procname = "redirect_load",
3274 .data = &ip_rt_redirect_load,
3275 .maxlen = sizeof(int),
3276 .mode = 0644,
3277 .proc_handler = proc_dointvec,
3278 },
3279 {
3280 .procname = "redirect_number",
3281 .data = &ip_rt_redirect_number,
3282 .maxlen = sizeof(int),
3283 .mode = 0644,
3284 .proc_handler = proc_dointvec,
3285 },
3286 {
3287 .procname = "redirect_silence",
3288 .data = &ip_rt_redirect_silence,
3289 .maxlen = sizeof(int),
3290 .mode = 0644,
3291 .proc_handler = proc_dointvec,
3292 },
3293 {
3294 .procname = "error_cost",
3295 .data = &ip_rt_error_cost,
3296 .maxlen = sizeof(int),
3297 .mode = 0644,
3298 .proc_handler = proc_dointvec,
3299 },
3300 {
3301 .procname = "error_burst",
3302 .data = &ip_rt_error_burst,
3303 .maxlen = sizeof(int),
3304 .mode = 0644,
3305 .proc_handler = proc_dointvec,
3306 },
3307 {
3308 .procname = "gc_elasticity",
3309 .data = &ip_rt_gc_elasticity,
3310 .maxlen = sizeof(int),
3311 .mode = 0644,
3312 .proc_handler = proc_dointvec,
3313 },
3314 {
3315 .procname = "mtu_expires",
3316 .data = &ip_rt_mtu_expires,
3317 .maxlen = sizeof(int),
3318 .mode = 0644,
3319 .proc_handler = proc_dointvec_jiffies,
3320 },
3321 {
3322 .procname = "min_pmtu",
3323 .data = &ip_rt_min_pmtu,
3324 .maxlen = sizeof(int),
3325 .mode = 0644,
3326 .proc_handler = proc_dointvec,
3327 },
3328 {
3329 .procname = "min_adv_mss",
3330 .data = &ip_rt_min_advmss,
3331 .maxlen = sizeof(int),
3332 .mode = 0644,
3333 .proc_handler = proc_dointvec,
3334 },
3335 { }
3336 };
3337
3338 static struct ctl_table empty[1];
3339
3340 static struct ctl_table ipv4_skeleton[] =
3341 {
3342 { .procname = "route",
3343 .mode = 0555, .child = ipv4_route_table},
3344 { .procname = "neigh",
3345 .mode = 0555, .child = empty},
3346 { }
3347 };
3348
3349 static __net_initdata struct ctl_path ipv4_path[] = {
3350 { .procname = "net", },
3351 { .procname = "ipv4", },
3352 { },
3353 };
3354
3355 static struct ctl_table ipv4_route_flush_table[] = {
3356 {
3357 .procname = "flush",
3358 .maxlen = sizeof(int),
3359 .mode = 0200,
3360 .proc_handler = ipv4_sysctl_rtcache_flush,
3361 },
3362 { },
3363 };
3364
3365 static __net_initdata struct ctl_path ipv4_route_path[] = {
3366 { .procname = "net", },
3367 { .procname = "ipv4", },
3368 { .procname = "route", },
3369 { },
3370 };
3371
3372 static __net_init int sysctl_route_net_init(struct net *net)
3373 {
3374 struct ctl_table *tbl;
3375
3376 tbl = ipv4_route_flush_table;
3377 if (!net_eq(net, &init_net)) {
3378 tbl = kmemdup(tbl, sizeof(ipv4_route_flush_table), GFP_KERNEL);
3379 if (tbl == NULL)
3380 goto err_dup;
3381 }
3382 tbl[0].extra1 = net;
3383
3384 net->ipv4.route_hdr =
3385 register_net_sysctl_table(net, ipv4_route_path, tbl);
3386 if (net->ipv4.route_hdr == NULL)
3387 goto err_reg;
3388 return 0;
3389
3390 err_reg:
3391 if (tbl != ipv4_route_flush_table)
3392 kfree(tbl);
3393 err_dup:
3394 return -ENOMEM;
3395 }
3396
3397 static __net_exit void sysctl_route_net_exit(struct net *net)
3398 {
3399 struct ctl_table *tbl;
3400
3401 tbl = net->ipv4.route_hdr->ctl_table_arg;
3402 unregister_net_sysctl_table(net->ipv4.route_hdr);
3403 BUG_ON(tbl == ipv4_route_flush_table);
3404 kfree(tbl);
3405 }
3406
3407 static __net_initdata struct pernet_operations sysctl_route_ops = {
3408 .init = sysctl_route_net_init,
3409 .exit = sysctl_route_net_exit,
3410 };
3411 #endif
3412
3413 static __net_init int rt_genid_init(struct net *net)
3414 {
3415 get_random_bytes(&net->ipv4.rt_genid,
3416 sizeof(net->ipv4.rt_genid));
3417 get_random_bytes(&net->ipv4.dev_addr_genid,
3418 sizeof(net->ipv4.dev_addr_genid));
3419 return 0;
3420 }
3421
3422 static __net_initdata struct pernet_operations rt_genid_ops = {
3423 .init = rt_genid_init,
3424 };
3425
3426
3427 #ifdef CONFIG_IP_ROUTE_CLASSID
3428 struct ip_rt_acct __percpu *ip_rt_acct __read_mostly;
3429 #endif /* CONFIG_IP_ROUTE_CLASSID */
3430
3431 static __initdata unsigned long rhash_entries;
3432 static int __init set_rhash_entries(char *str)
3433 {
3434 if (!str)
3435 return 0;
3436 rhash_entries = simple_strtoul(str, &str, 0);
3437 return 1;
3438 }
3439 __setup("rhash_entries=", set_rhash_entries);
3440
3441 int __init ip_rt_init(void)
3442 {
3443 int rc = 0;
3444
3445 #ifdef CONFIG_IP_ROUTE_CLASSID
3446 ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct), __alignof__(struct ip_rt_acct));
3447 if (!ip_rt_acct)
3448 panic("IP: failed to allocate ip_rt_acct\n");
3449 #endif
3450
3451 ipv4_dst_ops.kmem_cachep =
3452 kmem_cache_create("ip_dst_cache", sizeof(struct rtable), 0,
3453 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
3454
3455 ipv4_dst_blackhole_ops.kmem_cachep = ipv4_dst_ops.kmem_cachep;
3456
3457 if (dst_entries_init(&ipv4_dst_ops) < 0)
3458 panic("IP: failed to allocate ipv4_dst_ops counter\n");
3459
3460 if (dst_entries_init(&ipv4_dst_blackhole_ops) < 0)
3461 panic("IP: failed to allocate ipv4_dst_blackhole_ops counter\n");
3462
3463 rt_hash_table = (struct rt_hash_bucket *)
3464 alloc_large_system_hash("IP route cache",
3465 sizeof(struct rt_hash_bucket),
3466 rhash_entries,
3467 (totalram_pages >= 128 * 1024) ?
3468 15 : 17,
3469 0,
3470 &rt_hash_log,
3471 &rt_hash_mask,
3472 rhash_entries ? 0 : 512 * 1024);
3473 memset(rt_hash_table, 0, (rt_hash_mask + 1) * sizeof(struct rt_hash_bucket));
3474 rt_hash_lock_init();
3475
3476 ipv4_dst_ops.gc_thresh = (rt_hash_mask + 1);
3477 ip_rt_max_size = (rt_hash_mask + 1) * 16;
3478
3479 devinet_init();
3480 ip_fib_init();
3481
3482 INIT_DELAYED_WORK_DEFERRABLE(&expires_work, rt_worker_func);
3483 expires_ljiffies = jiffies;
3484 schedule_delayed_work(&expires_work,
3485 net_random() % ip_rt_gc_interval + ip_rt_gc_interval);
3486
3487 if (ip_rt_proc_init())
3488 printk(KERN_ERR "Unable to create route proc files\n");
3489 #ifdef CONFIG_XFRM
3490 xfrm_init();
3491 xfrm4_init(ip_rt_max_size);
3492 #endif
3493 rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL, NULL);
3494
3495 #ifdef CONFIG_SYSCTL
3496 register_pernet_subsys(&sysctl_route_ops);
3497 #endif
3498 register_pernet_subsys(&rt_genid_ops);
3499 return rc;
3500 }
3501
3502 #ifdef CONFIG_SYSCTL
3503 /*
3504 * We really need to sanitize the damn ipv4 init order, then all
3505 * this nonsense will go away.
3506 */
3507 void __init ip_static_sysctl_init(void)
3508 {
3509 register_sysctl_paths(ipv4_path, ipv4_skeleton);
3510 }
3511 #endif
Linux with added FPC-III support